Organic light-emitting device and apparatus including the same

ABSTRACT

An organic light emitting device includes: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode, the organic layer including an emission layer that includes a first emission layer, a second emission layer, and a third emission layer, wherein at least one of the first emission layer, the second emission layer, or the third emission layer includes at least one first compound, and formulae for the first compound include at least one 15N.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2020-0076754, filed on Jun. 23, 2020, in the Korean Intellectual Property Office, the entire content of which is incorporated herein by reference.

BACKGROUND 1. Field

One or more aspects of embodiments of the present disclosure relate to an organic light-emitting device and an apparatus including the same.

2. Description of Related Art

Organic light-emitting devices are self-emission devices that, as compared with related devices, have wide viewing angles, high contrast ratios, short response times, and excellent characteristics in terms of luminance, driving voltage, and/or response speed, and produce full-color images.

The organic light-emitting devices may include a first electrode located on a substrate, and a hole transport region, an emission layer, an electron transport region, and a second electrode sequentially stacked on the first electrode. Holes provided from the first electrode may move toward the emission layer through the hole transport region, and electrons provided from the second electrode may move toward the emission layer through the electron transport region. Carriers, such as the holes and the electrons, recombine in the emission layer to produce excitons. These excitons transit from an excited state to a ground state to thereby generate light.

SUMMARY

One or more aspects of embodiments of the present disclosure are directed toward an organic light-emitting device and an apparatus including the same.

Additional aspects will be set forth in part in the description which follows and, in part, will be apparent from the description, or may be learned by practice of the presented embodiments of the disclosure.

According to one or more embodiments, provided is an organic light-emitting device including a first electrode, a second electrode facing the first electrode, and

an organic layer between the first electrode and the second electrode and including an emission layer that includes a first emission layer, a second emission layer, and a third emission layer,

wherein at least one of the first emission layer, the second emission layer, or the third emission layer includes at least one first compound, and

the first compound includes at least one ¹⁵N and is represented by one of Formula 1-1, Formula 1-2, Formula 2-1 to Formula 2-3, and Formula 3.

In Formulae 1-1, 1-2, 2-1 to 2-3, and 3,

N* is ¹⁵N, and N*¹ and N*² are each independently ¹⁴N or ¹⁵N, wherein at least one of N*¹ or N*² is ¹⁵N,

A₂₁ to A₂₄ and A₃₁ to A₃₃ are each independently selected from a C₃-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclic group,

A₃₁ and A₃₂ are optionally linked to each other via a first linking group,

X₂₁ is O, S, or N*′-[(L₂₄)_(a24)-Ar₂₄],

Y₂₁ and Y₂₂ are each independently a single bond, *—O—*′, *—S—*′, *—N*′(R₂₅)—*′, *—C(R₂₅)(R₂₆)—*′, *—Si(R₂₅)(R₂₆)*′, or *—C(R₂₅)═C(R₂₆)—*′,

c21 and c22 are each independently an integer from 1 to 3,

X₃₁ is B, P, P(═O), P(═S), Ga, As, Si(R₂₇), or Ge(R₂₇),

L₁₁ to L₁₄, L₂₁ to L₂₄, and L₃₁ to L₃₅ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₁₅ is *—O—*′, *—S—*′, *—Se—*′, *—N*′(Ar₁₅)—*′, a substituted or unsubstituted C₃-C₆₀ carbocyclic group, or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

a11 to a14, a21 to a24, and a31 to a35 are each independently an integer from 0 to 5,

a15 is an integer from 1 to 10,

Ar₁₁ to Ar₁₅, Ar₂₁ to Ar₂₄, and Ar₃₁ to Ar₃₃ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆ heterocyclic group,

b21, b22, and b31 to b33 are each independently an integer from 0 to 10,

R₂₁ to R₂₇ and R₃₁ to R₃₅ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N*(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂),

d21 to d24 and d31 to d33 are each independently an integer from 0 to 10,

at least one substituent of the substituted C₃-C₃₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from:

deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group,

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —O(Q₁₁), —S(Q₁₁), —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —P(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂),

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group,

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —O(Q₂₁), —S(Q₂₁), —Si(Q₂₁)(Q₂₂)(Q₂₃), —N*′(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —P(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂), and

—O(Q₃₁), —S(Q₃₁), —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —P(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a C₁-C₆₀ alkyl group that is substituted with at least one selected from deuterium, —F, a cyano group, a C₁-C₆ alkyl group, a phenyl group, and a biphenyl group, and a C₆-C₆₀ aryl group that is substituted with at least one selected from deuterium, —F, a cyano group, a C₁-C₁₀ alkyl group, a phenyl group, and a biphenyl group,

when a heteroatom included in the C₁-C₆₀ heterocyclic group, the C₁-C₁₀ heterocycloalkyl group, the C₁-C₁₀ heterocycloalkenyl group, the C₁-C₆₀ heteroaryl group, and the monovalent non-aromatic condensed heteropolycyclic group is each independently a nitrogen atom, and the nitrogen atom is ¹⁴N or ¹⁵N,

a nitrogen atom included in the cyano group, the nitro group, the amino group, the amidino group, the hydrazine group, the hydrazone group is ¹⁴N or ¹⁵N, and

N*′ is ¹⁴N or ¹⁵N, wherein * and *′ each indicate a binding site to a neighboring atom in addition to *′ in N*′.

According to one or more embodiments, provided is an organic light-emitting device including a first pixel electrode, a second pixel electrode, and a third pixel electrode, respectively in a first emission area, a second emission area, and a third emission area; an opposite electrode facing the first pixel electrode, the second pixel electrode, and the third pixel electrode; and an organic layer between the opposite electrode and the first pixel electrode, the second pixel electrode, and the third pixel electrode, the organic layer including an emission layer,

wherein the emission layer includes:

a first emission layer arranged to correspond to the first emission area and to emit a first-color light, a second emission layer arranged to correspond to the second emission area and to emit a second-color light, and a third emission layer arranged to correspond to the third emission area and to emit a third-color light,

at least one of the first emission layer, the second emission layer, or the third emission layer includes at least one first compound.

According to one or more embodiments, provided is an organic light-emitting device including a first electrode, a second electrode facing the first electrode, and m emission units between the first electrode and the second electrode, wherein the m is an integer of 2 or more, each m emission unit includes an organic layer including an emission layer, and

at least one of m emission layers included in the m emission units includes at least one first compound.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other aspects, features, and advantages of certain embodiments of the disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which

FIGS. 1-6 are each a schematic cross-sectional view of a structure of an organic light-emitting device according to one or more embodiments.

DETAILED DESCRIPTION

Reference will now be made in more detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. In this regard, the present embodiments may have different forms and should not be construed as being limited to the descriptions set forth herein. Accordingly, the embodiments are merely described below, by referring to the figures, to explain aspects of the present description. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression “at least one of a, b or c” indicates only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof. Further, the use of “may” when describing embodiments of the present disclosure refers to “one or more embodiments of the present disclosure.”

Because the disclosure may have diverse modified embodiments, example embodiments are illustrated in the drawings and are described in the detailed description. An effect and a characteristic of the disclosure, and a method of accomplishing these will be apparent when referring to embodiments described with reference to the drawings. The disclosure may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

One or more embodiments of the disclosure will be described below in more detail with reference to the accompanying drawings. Those components that are the same or are in correspondence with each other are rendered the same reference numeral regardless of the figure number, and redundant explanations are omitted.

It will be understood that although the terms “first,” “second,” etc. may be used herein to describe various components, these components should not be limited by these terms. These components are only used to distinguish one component from another.

An expression used in the singular encompasses the expression of the plural, unless it has a clearly different meaning in the context.

It will be further understood that the terms “comprises” and/or “comprising” used herein specify the presence of stated features or elements, but do not preclude the presence or addition of one or more other features or elements.

In the following embodiments, when various components such as layers, films, regions, plates, etc. are said to be “on” another component, this may include not only a case in which other components are “immediately (or directly) on” the layers, films, regions, or plates (without intervening elements therebetween), but also a case in which other components may be placed therebetween. Sizes of elements in the drawings may be exaggerated for convenience of explanation. In other words, because sizes and thicknesses of components in the drawings are arbitrarily illustrated for convenience of explanation, the following embodiments are not limited thereto.

An organic light-emitting device includes: a first electrode;

a second electrode facing the first electrode; and

an organic layer between the first electrode and the second electrode, and

the organic layer includes an emission layer that includes a first emission layer, a second emission layer, and a third emission layer,

wherein at least one of the first emission layer, the second emission layer, or the third emission layer includes at least one first compound, and

the first compound includes at least one ¹⁵N and is represented by one of Formula 1-1, Formula 1-2, Formulae 2-1 to 2-3, or Formula 3:

In Formula 1-1, Formula 1-2, Formulae 2-1 to Formula 2-3, and Formula 3,

N* is ¹⁵N, and N*¹ and N*² are each independently ¹⁴N or ¹⁵N, wherein at least one of N*¹ or N*² is ¹⁵N.

In one or more embodiments, an emission layer including a first compound from among the first emission layer to the third emission layer may not include (e.g., may omit) a compound having a structure in which ¹⁵N of the first compound is substituted with (e.g., substituted for)¹⁴N.

In one or more embodiments, N*¹ and N*² may be ¹⁵N.

In Formula 2-1 to Formula 2-3 and Formula 3, A₂₁ to A₂₄ and A₃₁ to A₃₃ may each independently be selected from a C₃-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclic group, and A₃₁ and A₃₂ may optionally be linked to each other via a first linking group.

In one or more embodiments, A₂₁ to A₂₄ and A₃₁ to A₃₃ may each independently be:

a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a thiophene group, a furan group, a borole group, a silole group, a germole group, an indole group, a benzoborole group, a benzophosphole group, an indene group, a benzosilole group, a benzogermole group, a benzothiophene group, a benzoselenophene group, a benzofuran group, a carbazole group, a dibenzoborole group, a dibenzophosphole group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a fluoranthene group, a perylene group, a benzocarbazole group, a dibenzocarbazole group, a dibenzosilole group, a dibenzogermole group, a dibenzothiophene group, a dibenzoselenophene group, a dibenzofuran group, a naphthofuran group, a benzonaphthofuran group, a dinaphthofuran group, a naphthothiophene group, a benzonaphthothiophene group, a dinaphthothiophene group, a dibenzothiophene 5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azaindole group, an azabenzoborole group, an azabenzophosphole group, an azaindene group, an azabenzosilole group, an azabenzogermole group, an azabenzothiophene group, an azabenzoselenophene group, an azabenzofuran group, an azacarbazole group, an azadibenzoborole group, an azadibenzophosphole group, an azafluorene group, an azadibenzosilole group, an azadibenzogermole group, an azadibenzothiophene group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, or a 5,6,7,8-tetrahydroquinoline group.

For example, A₂₁ to A₂₄ and A₃₁ to A₃₃ may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a thiophene group, a furan group, a silole group, a carbazole group, an indole group, an isoindole group, a benzofuran group, a benzothiophene group, a benzosilole group, a dibenzofuran group, a dibenzothiophene group, a benzocarbazole group, a dibenzocarbazole group, and a dibenzosilole group.

For example, A₂₁ to A₂₄ and A₃₁ to A₃₃ may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a phenanthrene group, an anthracene group, a triphenylene group, a pyrene group, a chrysene group, a perylene group, a carbazole group, a dibenzofuran group, and a dibenzothiophene group, but embodiments of the present disclosure are not limited thereto.

For example, A₂₁ to A₂₄ and A₃₁ to A₃₃ may each independently be selected from a benzene group, a naphthalene group, and a carbazole group, but embodiments of the present disclosure are not limited thereto.

For example, A₂₁ to A₂₄ and A₃₁ to A₃₃ may be a benzene group or a carbazole group, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the first linking group may be selected from a single bond, *—O—*′, and *—S—*′.

In Formula 2-2, X₂₁ may be O, S, or N*′-[(L₂₄)_(a24)-Ar₂₄].

In one or more embodiments, X₂₁ may be N*′-[(L₂₄)_(a24)-Ar₂₄].

In Formulae 2-1 and 2-2, Y₂₁ and Y₂₂ may each independently be a single bond, *—O—*′, *—S—*′, *—N*′(R₂₅)—*′, *—C(R₂₅)(R₂₆)—*′, *—Si(R₂₅)(R₂₆)—*′, or *—C(R₂₅)═C(R₂₆)—*′.

In one or more embodiments, Y₂₁ and Y₂₂ may be a single bond.

In Formulae 2-1 and 2-2, c21 and c22 may each independently be an integer from 1 to 3. c21 and c22 are the number of groups represented by Y₂₁ and the number of groups represented by Y₂₂, respectively, wherein, when c21 is 2 or more, two or more of Y₂₁(s) may be identical to or different from each other, and when c22 is 2 or more, two or more of Y₂₂(s) may be identical to or different from each other.

In Formula 3, X₃₁ is B, P, P(═O), P(═S), Ga, As, Si(R₂₇), or Ge(R₂₇).

In one or more embodiments, X₃₁ may be B.

In Formula 1-1, Formula 1-2, Formulae 2-1 to Formula 2-3, and Formula 3, L₁₁ to L₁₄, L₂₁ to L₂₄, and L₃₁ to L₃₅ may each independently be a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, and

L₁₅ is *—O—*′, *—S—*′, *—Se—*′, *—N*′(Ar₁₅)—*′, a substituted or unsubstituted C₃-C₆₀ carbocyclic group, or a substituted or unsubstituted C₁-C₆₀ heterocyclic group.

In one or more embodiments, L₁₁ to L₁₄, L₂₁ to L₂₄, and L₃₁ to L₃₅ may each independently be selected from:

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group; and

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*′(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂),

L₁₅ is selected from: *—O—*′, *—S—*′, *—N*′(Ar₁₅)—*′, a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group;

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*′(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂),

Ar₁₅ is the same as defined in the present specification, and

Q₃₁ to Q₃₃ are each independently selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group.

For example, L₁₁ to L₁₄, L₂₁ to L₂₄, and L₃₁ to L₃₅ may each independently be selected from:

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a pyrene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group;

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a pyrene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*′(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group.

L₁₅ may be selected from: a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a pyrene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group,

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a pyrene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*′(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group.

In one or more embodiments, 11 to L₁₄, L₂₁ to L₂₄, L₃₁ to L₃₅ may each independently be selected from groups represented by Formulae 3-1 to 3-27, and L₁₅ may be selected from *—O—*′, *—S—*′, *—N*′(Ar₁₅)—*′, and groups represented by Formulae 3-1 to 3-27:

In Formulae 3-1 to 3-27,

Y₁₁ is selected from C(Z₃)(Z₄), N*′(Z₅), Si(Z₆)(Z₇), O, and S,

Z₁ to Z₇ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a benzofuranyl group, a benzothiophenyl group, a benzosilolyl group, a dibenzosilolyl group, —N*′(Q₃₁)(Q₃₂), and —Si(Q₃₁)(Q₃₂)(Q₃₃),

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group,

d2 may be an integer from 0 to 2,

d3 may be an integer from 0 to 3,

d4 may be an integer from 0 to 4,

d6 may be an integer from 0 to 6,

d8 may be an integer from 0 to 8, and

* and *′ each indicate a binding site to a neighboring atom.

In Formula 1-1, Formula 1-2, Formulae 2-1 to Formula 2-3, and Formula 3, a11 to a14, a21 to a24, and a31 to a35 may each independently be an integer from 0 to 5, and a15 may be an integer from 1 to 10. a11 to a14, a21 to a24, a31 to a35, and a15 are the number of groups represented by 11 to L₁₄, the number of groups represented by L₂₁ to L₂₄, the number of groups represented by L₃₁ to L₃₅, and the number of groups represented by L₁₅, respectively, wherein, when a11 is 2 or more, two or more of L₁₁(s) may be identical to or different from each other, when a12 is 2 or more, two or more of L₁₂(s) may be identical to or different from each other, when a13 is 2 or more, two or more of L₁₃(s) may be identical to or different from each other, when a14 is 2 or more, two or more of L₁₄(s) may be identical to or different from each other, when a21 is 2 or more, two or more of L₂₁(s) may be identical to or different from each other, when a22 is 2 or more, two or more of L₂₂(s) may be identical to or different from each other, when a23 is 2 or more, two or more of L₂₃(s) may be identical to or different from each other, when a24 is 2 or more, two or more of L₂₄(s) may be identical to or different from each other, when a31 is two or more, two or more of L₃₁(s) may be identical to or different from each other, when a32 is 2 or more, two or more of L₃₂(s) may be identical to or different from each other, when a33 is 2 or more, two or more of L₃₃(s) may be identical to or different from each other, when a34 is 2 or more, two or more of L₃₄(s) may be identical to or different from each other, when a35 is 2 or more, two or more of L₃₅(s) may be identical to or different from each other, and when a15 is 2 or more, two or more of L₁₅(s) may be identical to or different from each other. When a11 is 0, (L₁₁)_(a11) is a single bond, when a12 is 0, (L₁₂)_(a12) is a single bond, when a13 is 0, (L₁₃)_(a13) is a single bond, when a14 is 0, (L₁₄)_(a14) is a single bond, when a21 is 0, (L₂₁)_(a21) is a single bond, when a22 is 0, (L₂₂)_(a22) is a single bond, when a23 is 0, (L₂₃)_(a23) is a single bond, when a24 is 0, (L₂₄)_(a24) is a single bond, when a31 is 0, (L₃₁)_(a31) is a single bond, when a32 is 0, (L₃₂)_(a32) is a single bond, when a33 is 0, (L₃₃)_(a33) is a single bond, when a34 is 0, (L₃₄)_(a34) is a single bond, and when a35 is 0, (L₃₅)_(a35) is a single bond.

In Formula 1-1, Formula 1-2, Formulae 2-1 to Formula 2-3, and Formula 3, Ar₁₁ to Ar₁₅, Ar₂₁ to Ar₂₄, and Ar₃₁ to Ar₃₃ may each independently be a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group.

In one or more embodiments, Ar₁₁ to Ar₁₅, Ar₂₁ to Ar₂₄, and Ar₃₁ to Ar₃₃ may each independently be selected from:

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group; and

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*′(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group.

For example, Ar₁₁ to Ar₁₅, Ar₂₁ to Ar₂₄, and Ar₃₁ to Ar₃₃ may each independently be selected from:

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a pyrene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group; and

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a pyrene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, an anthracenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*′(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂), and

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group.

In one or more embodiments, Ar₁₁ to Ar₁₅, Ar₂₁ to Ar₂₄, and Ar₃₁ to Ar₃₃ may each independently be a group represented by any one of Formulae 4-1 to 4-21:

In Formulae 4-1 to 4-21,

Y₃₁ may be O, S, C(Z₃₃)(Z₃₄), N*′(Z₃₅), or Si(Z₃₆)(Z₃₇),

Z₃₁ to Z₃₇ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a benzosilolyl group, a dibenzosilolyl group, —N*′(Q₃₁)(Q₃₂), and —Si(Q₃₁)(Q₃₂)(Q₃₃),

Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group,

e2 may be an integer from 0 to 2,

e3 may be an integer from 0 to 3,

e4 may be an integer from 0 to 4,

e5 may be an integer from 0 to 5,

e6 may be an integer from 0 to 6,

e7 may be an integer from 0 to 7,

e9 may be an integer from 0 to 9, and

* indicates a binding site to a neighboring atom.

In Formula 1-1, Formula 1-2, Formulae 2-1 to Formula 2-3, and Formula 3, b21, b22, and b31 to b33 may each independently be an integer from 0 to 10.

b21, b22, and b31 to b33 are respectively the number of groups represented by [(L₂₁)_(a21)-Ar₂₁], the number of groups represented by [(L₂₂)_(a22)-Ar₂₂], the number of groups represented by [(L₃₁)_(a31)-Ar₃₁], the number of groups represented by [(L₃₂)_(a32)-Ar₃₂], the number of groups represented by [(L₃₃)_(a33)-Ar₃₃], wherein, when b21, b22, and b31 to b33 are each independently 0, the groups represented by [(L₂₁)_(a21)-Ar₂₁], [(L₂₂)_(a22)-Ar₂₂], [(L₃₁)_(a31)-Ar₃₁], [(L₃₂)_(a32)-Ar₃₂], and [(L₃₃)_(a33)-Ar₃₃] may each independently be hydrogen, when b21 is 2 or more, two or more groups represented by [(L₂₁)_(a21)-Ar₂₁](s) may be identical to or different from each other, when b22 is 2 or more, two or more groups represented by [(L₂₂)_(a22)-Ar₂₂](s) may be identical to or different from each other, when b31 is 2 or more, two or more groups represented by [(L₃₁)_(a31)-Ar₃₁](s) may be identical to or different from each other, when b32 is 2 or more, two or more groups represented by [(L₃₂)_(a32)-Ar₃₂](s) may be identical to or different from each other, and when b33 is 2 or more, two or more groups represented by [(L₃₃)_(a33)-Ar₃₃](s) may be identical to or different from each other.

In Formulae 2-1 to Formula 2-3 and Formula 3, R₂₁ to R₂₇ and R₃₁ to R₃₅ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N*′(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂).

In one or more embodiments, R₂₁ to R₂₇ and R₃₁ to R₃₅ may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, an imidazopyrimidine group, —Si(Q₁)(Q₂)(Q₃), —N*′(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂); and

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, and a terphenyl group, and

Q₁ to Q₃ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group.

For example, R₂₁ to R₂₇ and R₃₁ to R₃₅ may each independently be selected from hydrogen, a C₁-C₂₀ alkyl group, —CF₃, and groups represented by Formulae 5-1 to 5-3:

In Formulae 5-1 to 5-3,

Y₄₁ may be O, S, C(Z₄₃)(Z₄₄), N*′(Z₄₅), or Si(Z₄₆)(Z₄₇),

Z₄₁ to Z₄₇ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a benzosilolyl group, a dibenzosilolyl group, —N*′(Q₄₁)(Q₄₂), and —Si(Q₄₁)(Q₄₂)(Q₄₃),

Q₄₁ to Q₄₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group,

f3 is an integer from 0 to 3,

f4 is an integer from 0 to 4,

f5 is an integer from 0 to 5, and

* indicates a binding site to a neighboring atom.

In Formula 2-1 to Formula 2-3 and Formula 3, d21 to d24 and d31 to d33 may each independently be an integer from 0 to 10.

In the present specification, when a heteroatom included in the C₁-C₆₀ heterocyclic group, the C₁-C₁₀ heterocycloalkyl group, the C₁-C₁₀ heterocycloalkenyl group, the C₁-C₆₀ heteroaryl group, and the monovalent non-aromatic condensed heteropolycyclic group is a nitrogen atom, the nitrogen atom is ¹⁴N or ¹⁵N,

a nitrogen atom included in the cyano group, the nitro group, the amino group, the amidino group, the hydrazine group, and the hydrazone group is ¹⁴N or ¹⁵N, and

N*′ is ¹⁴N or ¹⁵N.

For example, N*′ may all be ¹⁵N.

In one or more embodiments, the first compound may be represented by any one of Formulae 1-1(1) and 1-1(2) below, Formula 1-2 described above, Formulae 2-1(1) to 2-1(3) and 2-2(1) below, Formula 2-3 described above, and Formula 3 described above:

In Formulae 1-1(1), 1-1(2), 2-1(1) to 2-1(3), and 2-2(1),

N*, 11 to L₁₃, L₂₃, L₂₄, a11 to a13, a23, a24, Ar₁₁, Ar₁₂, Ar₂₃, and Ar₂₄ are the same as described above,

Z_(a) to Z_(d) may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a silolyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, a benzosilolyl group, a dibenzosilolyl group, —N*′(Q₄₁)(Q₄₂), and —Si(Q₄₁)(Q₄₂)(Q₄₃),

Q₄₁ to Q₄₃ may each independently be selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group,

x2 may be an integer from 0 to 2,

x3 may be an integer from 0 to 3, and

x4 may be an integer from 0 to 4.

In one or more embodiments, the first compound may include at least one ¹⁵N.

In one or more embodiments, the first compound may include at least one C-¹⁵N bond.

In one or more embodiments, all carbon-nitrogen single bonds included in the first compound may be C—¹⁵N bonds.

In one or more embodiments, the first compound may be selected from Compounds 1 to 18, but embodiments of the present disclosure are not limited thereto:

Therefore, by including the first compound, the organic light-emitting device may have high efficiency and long lifespan, while maintaining other existing characteristics, as compared to a material in which ¹⁵N is not substituted.

In addition, the organic light-emitting device including the first compound does not further include a compound in which ¹⁵N (in the formula structure of the first compound) is substituted with (e.g., substituted for)¹⁴N (e.g., the organic light-emitting device does not include a compound having the same formula structure as that of the first compound, except ¹⁵N is substituted with (e.g., substituted for)¹⁴N), and thus, the organic light-emitting device may be substantially free from problems such as a difference in a ratio due to a difference in deposition temperature, a change in a deposition rate, and/or a difference over time, which may otherwise occur during a deposition process when there is a mixture heterogeneous molecules having molecular weight as the only difference between them.

A synthesis method of the first compound should be recognizable by one of ordinary skill in the art by referring to Examples provided below.

The expression “includes at least one first compound” as used herein may be interpreted as “may include one or more of the same first compound or at least two of the first compound that are different from each other and belong to a range of Formulae 1-1, 1-2, 2-1, 2-2, and 3.”

In one or more embodiments, the organic light-emitting device may include, as the first compound, Compound 1. In one or more embodiments, the organic light-emitting device may include, as the first compound, Compound 1 and Compound 2. In this embodiment, Compounds 1 and 2 may be included in the same layer (for example, both Compounds 1 and 2 may be included in an emission layer) or in different layers (for example, Compound 1 may be included in an emission layer, and Compound 2 may be included in an electron transport layer).

In one or more embodiments,

the first electrode of the organic light-emitting device may be an anode,

the second electrode of the organic light-emitting device may be a cathode,

the organic layer may include at least one first compound,

the organic layer may further include a hole transport region between the first electrode and the emission layer, and an electron transport region between the emission layer and the second electrode,

the hole transport region may include a hole injection layer, a hole transport layer, an emission auxiliary layer, an electron blocking layer, or any combination thereof, and

the electron transport region may include a hole blocking layer, an electron transport layer, an electron injection layer, or any combination thereof.

In one or more embodiments, at least one of the first emission layer, the second emission layer, or the third emission layer may include a dopant and a host, and

the host may include at least one first compound.

In one or more embodiments, the host may include one of the first compound.

In one or more embodiments the host may include at least two of the first compound,

at least one first compound may be a hole transport host, and

at least one first compound may be an electron transport host.

In one or more embodiments, an amount of the first compound may be 50 parts by weight to 99.9 parts by weight based on 100 parts by weight of the emission layer.

For example, the dopant may not include ¹⁵N and may have a formula different from that of the first compound.

For example, the dopant may be a fluorescent, phosphorescent, or delayed fluorescent dopant.

In one or more embodiments, at least one of the first emission layer, the second emission layer, or the third emission layer may include a dopant and a host, and

the dopant may include at least one first compound.

In one or more embodiments, an amount of the first compound may be 0.01 parts by weight to 49.9 parts by weight based on 100 parts by weight of the emission layer.

For example, the host may not include ¹⁵N and may have a formula different from that of the first compound.

In one or more embodiments, at least one of the first emission layer, the second emission layer, or the third emission layer may include a dopant and a host,

the host may include at least one first compound, and the dopant may include at least one first compound.

In one or more embodiments, a first compound included in the host may be different from a first compound included in the dopant.

In one or more embodiments, the first emission layer may emit first-color light, the second emission layer may emit second-color light, the third emission layer may emit third-color light,

a maximum luminescence wavelength of the first-color light, a maximum luminescence wavelength of the second-color light, and a maximum luminescence wavelength of the third-color light may be identical to or different from each other, and

the first-color light and the second-color light may be emitted in the form of mixed light, or the first-color light, the second-color light, and the third-color light may be emitted in the form of mixed light.

According to one or more embodiments, provided is an organic light-emitting device including: a first pixel electrode, a second pixel electrode, and a third pixel electrode, respectively arranged in a first emission area, a second emission area, and a third emission area;

an opposite electrode facing the first pixel electrode, the second pixel electrode, and the third pixel electrode; and

an organic layer arranged between the opposite electrode and the first pixel electrode, the second pixel electrode, and the third pixel electrode, the organic layer including an emission layer,

wherein the emission layer includes:

a first emission layer arranged to correspond to the first emission area and to emit first-color light;

a second emission layer arranged to correspond to the second emission area and to emit second-color light; and

a third emission layer arranged to correspond to the third emission area and to emit third-color light, and

at least one of the first emission layer, the second emission layer, or the third emission layer includes at least one first compound.

According to one or more embodiments, provided is an organic light-emitting device including: a first electrode;

a second electrode facing the first electrode; and

m emission units between the first electrode and the second electrode,

wherein m is an integer of 2 or more,

the m emission units each include an emission layer, and

at least one of m emission layers included in the m emission units includes at least one first compound.

In one embodiment, the emission layer may be a first-color-light emission layer,

the organic light-emitting device may further include, between the first electrode and the second electrode, i) at least one second-color-light emission layer or ii) at least one second-color-light emission layer and at least one third-color-light emission layer,

a maximum luminescence wavelength of the first-color light, a maximum luminescence wavelength of the second-color light, and a maximum luminescence wavelength of the third-color light may be identical to or different from each other, and

the first-color light and the second-color light may be emitted in the form of mixed light, or the first-color light, the second-color light, and the third-color light may be emitted in the form of mixed light.

In one or more embodiments, the first-color light to third-color light may be red light. In one or more embodiments, the first-color light to third-color light may be green light. In one or more embodiments, the first-color light to third-color light may be blue light.

In one or more embodiments, the first-color light and the second-color light may be red light, and the third-color light may be green light. In one or more embodiments, the first-color light and the second-color light may be red light, and the third-color light may be blue light. In one or more embodiments, the first-color light and the second-color light may be green light, and the third-color light may be blue light. In one or more embodiments, the first-color light and the second-color light may be green light, and the third-color light may be red light. In one or more embodiments, the first-color light and the second-color light may be blue light, and the third-color light may be red light. In one or more embodiments, the first-color light and the second-color light may be blue light, and the third-color light may be green light.

In one or more embodiments, the first-color light and the third-color light may be red light, and the second-color light may be green light. In one or more embodiments, the first-color light and the third-color light may be red light, and the second-color light may be blue light. In one or more embodiments, the first-color light and the third-color light may be green light, and the second-color light may be blue light. In one or more embodiments, the first-color light and the third-color light may be green light, and the second-color light may be red light. In one or more embodiments, the first-color light and the third-color light may be blue light, and the second-color light may be red light. In one or more embodiments, the first-color light and the third-color light may be blue light, and the second-color light may be green light.

In one or more embodiments, the second-color light and the third-color light may be red light, and the first-color light may be green light. In one or more embodiments, the second-color light and the third-color light may be red light, and the first-color light may be blue light. In one or more embodiments, the second-color light and the third-color light may be green light, and the first-color light may be blue light. In one or more embodiments the second-color light and the third-color light may be green light, and the first-color light may be red light. In one or more embodiments, the second-color light and the third-color light may be blue light, and the first-color light may be red light. In one or more embodiments, the second-color light and the third-color light may be blue light, and the first-color light may be green light.

In one or more embodiments, the first-color light may be red light, the second-color light may be green light, and the third-color light may be blue light. In one or more embodiments, the first-color light may be red light, the second-color light may be blue light, and the third-color light may be blue light. In one or more embodiments, the first-color light may be green light, the second-color light may be red light, and the third-color light may be blue light. In one or more embodiments, the first-color light may be green light, the second-color light may be blue light, and the third-color light may be red light. In one or more embodiments, the first-color light may be blue light, the second-color light may be red light, and the third-color light may be green light. In one or more embodiments, the first-color light may be blue light, the second-color light may be green light, and the third-color light may be red light.

According to one or more embodiments, provided is an electronic apparatus including the organic light-emitting device and a thin-film transistor, wherein the first electrode of the organic light-emitting device electrically contacts one of a source electrode or a drain electrode of the thin-film transistor.

The term “organic layer” as used herein refers to a single layer and/or a plurality of layers between the first electrode and the second electrode of the organic light-emitting device. A material included in the “organic layer” is not limited to an organic material.

For example, the organic light-emitting device may have i) a stacked structure including a first electrode, an organic layer, a second electrode, and a second capping layer, which are sequentially stacked in this stated order, ii) a stacked structure including a first capping layer, a first electrode, an organic layer, and a second electrode, which are sequentially stacked in this stated order, or iii) a stacked structure including a first capping layer, a first electrode, an organic layer, a second electrode, and a second capping layer, which are sequentially stacked in this stated order, and at least one of the first capping layer or the second capping layer may include the heterocyclic compound.

The term “organic layer” used herein refers to a single layer and/or all layers between the first electrode and the second electrode of the organic light-emitting device. A material included in “the organic layer” is not limited to an organic material.

Description of FIG. 1

FIG. 1 is a schematic cross-sectional view of an organic light-emitting device 10 according to one or more embodiments. The organic light-emitting device 10 includes a first electrode 110, an organic layer 150, and a second electrode 190.

Hereinafter, a structure of the organic light-emitting device 10 according to one or more embodiments and a method of manufacturing the organic light-emitting device 10 will be described in connection with FIG. 1.

First Electrode 110

In FIG. 1, a substrate may be additionally located under the first electrode 110 or above the second electrode 190. The substrate may be a glass substrate and/or a plastic substrate, each having excellent mechanical strength, thermal stability, transparency, surface smoothness, ease of handling, and/or water resistance.

The first electrode 110 may be formed by, for example, depositing or sputtering a material for forming the first electrode 110 on the substrate. When the first electrode 110 is an anode, the material for forming the first electrode 110 may be selected from materials with a high work function to facilitate hole injection.

The first electrode 110 may be a reflective electrode, a semi-transmissive electrode, or a transmissive electrode. When the first electrode 110 is a transmissive electrode, a material for forming the first electrode 110 may be selected from indium tin oxide (ITO), indium zinc oxide (IZO), tin oxide (SnO₂), zinc oxide (ZnO), and any combination thereof, but embodiments of the present disclosure are not limited thereto. In one or more embodiments, when the first electrode 110 is a semi-transmissive electrode or a reflective electrode, a material for forming the first electrode 110 may be selected from magnesium (Mg), silver (Ag), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), and any combination thereof, but embodiments of the present disclosure are not limited thereto.

The first electrode 110 may have a single-layered structure, or a multi-layered structure including two or more layers. For example, the first electrode 110 may have a three-layered structure of ITO/Ag/ITO, but the structure of the first electrode 110 is not limited thereto.

Organic Layer 150

The organic layer 150 may be located on the first electrode 110. The organic layer 150 may include an emission layer.

The organic layer 150 may further include a hole transport region between the first electrode 110 and the emission layer, and an electron transport region between the emission layer and the second electrode 190.

Hole Transport Region in Organic Layer 150

The hole transport region may have i) a single-layered structure including (e.g., consisting of) a single layer including a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The hole transport region may include at least one layer selected from a hole injection layer, a hole transport layer, an emission auxiliary layer, and an electron blocking layer.

In one or more embodiments, the hole transport region may have a single-layered structure including a single layer including a plurality of different materials, or a multi-layered structure having a hole injection layer/hole transport layer structure, a hole injection layer/hole transport layer/emission auxiliary layer structure, a hole injection layer/emission auxiliary layer structure, a hole transport layer/emission auxiliary layer structure, or a hole injection layer/hole transport layer/electron blocking layer structure, wherein for each structure, constituting layers are sequentially stacked from the first electrode 110 in this stated order, but the structure of the hole transport region is not limited thereto.

The hole transport region may include at least one selected from m-MTDATA, TDATA, 2-TNATA, NPB(NPD), β-NPB, TPD, spiro-TPD, spiro-NPB, methylated NPB, TAPC, HMTPD, 4,4′,4″-tris(N-carbazolyl)triphenylamine (TCTA), polyaniline/dodecylbenzenesulfonic acid (PANI/DBSA), poly(3,4-ethylenedioxythiophene)/poly(4-styrenesulfonate) (PEDOT/PSS), polyaniline/camphor sulfonic acid (PANI/CSA), polyaniline/poly(4-styrenesulfonate) (PANI/PSS), a compound represented by Formula 201, and a compound represented by Formula 202:

In Formulae 201 and 202,

L₂₀₁ to L₂₀₄ are each independently selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

L₂₀₅ may be selected from *—O—*′, *—S—*′, *—N(Q₂₀₁)-*′, a substituted or unsubstituted C₁-C₂₀ alkylene group, a substituted or unsubstituted C₂-C₂₀ alkenylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xa1 to xa4 are each independently an integer from 0 to 3,

xa5 is an integer from 1 to 10, and

R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group.

For example, R₂₀₁ and R₂₀₂ in Formula 202 may optionally be linked to each other via a single bond, a dimethyl-methylene group, and/or a diphenyl-methylene group, and R₂₀₃ and R₂₀₄ may optionally be linked to each other via a single bond, a dimethyl-methylene group, and/or a diphenyl-methylene group.

In one or more embodiments, in Formulae 201 and 202,

L₂₀₁ to L₂₀₅ may each independently be selected from:

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a pentalenylene group, an indenylene group, a naphthylene group, an azulenylene group, a heptalenylene group, an indacenylene group, an acenaphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenalenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a naphthacenylene group, a picenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a rubicenylene group, a coronenylene group, an ovalenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃) and —N(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In one or more embodiments, xa1 to xa4 may each independently be 0, 1, or 2.

In one or more embodiments, xa5 may be 1, 2, 3, or 4.

In one or more embodiments, R₂₀₁ to R₂₀₄ and Q₂₀₁ may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), and —N(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ are the same as described above.

In one or more embodiments, at least one of R₂₀₁ to R₂₀₃ in Formula 201 may each independently be selected from:

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, in Formula 202, i) R₂₀₁ and R₂₀₂ may be linked to each other via a single bond, and/or ii) R₂₀₃ and R₂₀₄ may be linked to each other via a single bond.

In one or more embodiments, at least one of R₂₀₁ to R₂₀₄ in Formula 202 may be selected from:

a carbazolyl group; and

a carbazolyl group substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group,

but embodiments of the present disclosure are not limited thereto.

The compound represented by Formula 201 may be represented by Formula 201A below:

In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A(1) below, but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the compound represented by Formula 201 may be represented by Formula 201A-1 below, but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the compound represented by Formula 202 may be represented by Formula 202A below:

In one or more embodiments, the compound represented by Formula 202 may be represented by Formula 202A-1 below:

In Formulae 201A, 201A(1), 201A-1, 202A, and 202A-1,

L₂₀₁ to L₂₀₃, xa1 to xa3, xa5, and R₂₀₂ to R₂₀₄ are the same as described above,

R₂₁₁ and R₂₁₂ are the same as described in connection with R₂₀₃, and

R₂₁₃ to R₂₁₇ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a phenyl group substituted with a C₁-C₁₀ alkyl group, a phenyl group substituted with —F, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group.

The hole transport region may include at least one compound selected from compounds HT1 to HT39, but compounds to be included in the hole transport region are not limited thereto:

A thickness of the hole transport region may be in a range of about 100 Å to about 10,000 Å, for example, about 100 Å to about 1,000 Å. When the hole transport region includes at least one of a hole injection layer or a hole transport layer, a thickness of the hole injection layer may be in a range of about 100 Å to about 9,000 Å, for example, about 100 Å to about 1,500 Å, and a thickness of the hole transport layer may be in a range of about 50 Å to about 2,000 Å, for example, about 100 Å to about 1,500 Å. When the thicknesses of the hole transport region, the hole injection layer, and the hole transport layer are each independently within their respective ranges, satisfactory (or suitable) hole transporting characteristics may be obtained without a substantial increase in driving voltage.

The emission auxiliary layer may increase light-emission efficiency by compensating for an optical resonance distance according to the wavelength of light emitted by an emission layer, and the electron blocking layer may block or reduce the flow of electrons from an electron transport region. The emission auxiliary layer and the electron blocking layer may include the materials as described above.

p-Dopant

The hole transport region may further include, in addition to the materials described above, a charge-generating material for the improvement of conductive properties. The charge-generating material may be homogeneously or non-homogeneously dispersed in the hole transport region.

The charge-generating material may be, for example, a p-dopant.

In one or more embodiments, the p-dopant may have a lowest unoccupied molecular orbital (LUMO) energy level of about −3.5 eV or less.

The p-dopant may include at least one selected from a quinone derivative, a metal oxide, and a cyano group-containing compound, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the p-dopant may include at least one selected from:

a quinone derivative, such as tetracyanoquinodimethane (TCNQ) and/or 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4-TCNQ);

a metal oxide, such as tungsten oxide and/or molybdenum oxide;

1,4,5,8,9,12-hexaazatriphenylene-hexacarbonitrile (HAT-CN); and

a compound represented by Formula 221 below,

but embodiments of the present disclosure are not limited thereto:

In Formula 221,

R₂₂₁ to R₂₂₃ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and at least one of R₂₂₁ to R₂₂₃ may have at least one substituent selected from a cyano group, —F, —Cl, —Br, —I, a C₁-C₂₀ alkyl group substituted with —F, a C₁-C₂₀ alkyl group substituted with —Cl, a C₁-C₂₀ alkyl group substituted with —Br, and a C₁-C₂₀ alkyl group substituted with —I.

Emission Layer in Organic Layer 150

When the organic light-emitting device 10 is a full-color organic light-emitting device, the emission layer may be patterned into a red emission layer, a green emission layer, or a blue emission layer, according to a sub-pixel. In one or more embodiments, the emission layer may have a stacked structure of two or more layers selected from a red emission layer, a green emission layer, and a blue emission layer, in which the two or more layers contact each other or are separated from each other to emit white light. In one or more embodiments, the emission layer may include two or more materials selected from a red light-emitting material, a green light-emitting material, and a blue light-emitting material, in which the two or more materials are mixed with each other in a single layer to emit white light.

The emission layer may include a host and a dopant. The dopant may include at least one selected from a phosphorescent dopant, a fluorescent dopant, and a delayed fluorescent dopant. In some embodiments, the host, the fluorescent dopant, and/or the delayed fluorescent dopant may include the first compound.

An amount of a dopant in the emission layer may be, based on about 100 parts by weight of the host, in the range of about 0.01 parts by weight to about 15 parts by weight, but embodiments of the present disclosure are not limited thereto.

A thickness of the emission layer may be in a range of about 100 Å to about 1,000 Å, for example, about 200 Å to about 600 Å. When the thickness of the emission layer is within this range, excellent (or improved) light-emission characteristics may be obtained without a substantial increase in driving voltage.

Host in Emission Layer

The host may include the first compound.

In some embodiments, the host may include a compound represented by Formula 301:

[Ar₃₀₁]_(xb11)-[(L₃₀₁)_(xb1)-R₃₀₁]_(xb21).  Formula 301

In Formula 301,

Ar₃₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xb11 may be 1, 2, or 3,

L₃₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xb1 may be an integer from 0 to 5,

R₃₀₁ may be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₃₀₁)(Q₃₀₂)(Q₃₀₃), —N(Q₃₀₁)(Q₃₀₂), —B(Q₃₀₁)(Q₃₀₂), —C(═O)(Q₃₀₁), —S(═O)₂(Q₃₀₁), and —P(═O)(Q₃₀₁)(Q₃₀₂), and

xb21 may be an integer from 1 to 5,

wherein Q₃₀₁ to Q₃₀₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, Ar₃₀₁ in Formula 301 may be selected from:

a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, and a dibenzothiophene group; and

a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, and a dibenzothiophene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group, but embodiments of the present disclosure are not limited thereto.

When xb11 in Formula 301 is two or more, two or more of Ar₃₀₁(s) may be linked via a single bond.

In one or more embodiments, the compound represented by Formula 301 may be represented by Formula 301-1 or Formula 301-2:

In Formulae 301-1 and 301-2,

A₃₀₁ to A₃₀₄ may each independently be selected from a benzene ring, a naphthalene ring, a phenanthrene ring, a fluoranthene ring, a triphenylene ring, a pyrene ring, a chrysene ring, a pyridine ring, a pyrimidine ring, an indene ring, a fluorene ring, a spiro-bifluorene ring, a benzofluorene ring, a dibenzofluorene ring, an indole ring, a carbazole ring, a benzocarbazole ring, a dibenzocarbazole ring, a furan ring, a benzofuran ring, a dibenzofuran ring, a naphthofuran ring, a benzonaphthofuran ring, a dinaphthofuran ring, a thiophene ring, a benzothiophene ring, a dibenzothiophene ring, a naphthothiophene ring, a benzonaphthothiophene ring, and a dinaphthothiophene ring,

X₃₀₁ may be O, S, or N-[(L₃₀₄)_(xb4)-R₃₀₄],

R₃₁₁ to R₃₁₄ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

xb22 and xb23 may each independently be 0, 1, or 2,

L₃₀₁, xb1, R₃₀₁, and Q₃₁ to Q₃₃ are the same as described above,

L₃₀₂ to L₃₀₄ may each independently be the same as described in connection with L₃₀₁,

xb2 to xb4 may each independently be the same as described in connection with xb1, and

R₃₀₂ to R₃₀₄ may each independently be the same as described in connection with R₃₀₁.

For example, L₃₀₁ to L₃₀₄ in Formulae 301, 301-1, and 301-2 may each independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ are the same as described above.

In one or more embodiments, R₃₀₁ to R₃₀₄ in Formulae 301, 301-1, and 301-2 may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, an azacarbazolyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ are the same as described above.

In one or more embodiments, the host may include an alkaline earth metal complex. For example, the host may be selected from a Be complex (for example, Compound H55), an Mg complex, and a Zn complex.

The host may include at least one selected from 9,10-di(2-naphthyl)anthracene (ADN), 2-methyl-9,10-bis(naphthalen-2-yl)anthracene (MADN), 9,10-di-(2-naphthyl)-2-t-butyl-anthracene (TBADN), 4,4′-bis(N-carbazolyl)-1, 1′-biphenyl (CBP), 1,3-di-9-carbazolylbenzene (mCP), 1,3,5-tri(carbazol-9-yl)benzene (TCP), and Compounds H1 to H127, but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the host may include at least one of a silicon-containing compound (for example, BCPDS, and/or the like) or a phosphine oxide-containing compound (for example, POPCPA, and/or the like).

The host may include only one compound or may include at least two different compounds (for example, the host may include BCPDS and POPCPA). In one or more embodiment, the host may instead have other various suitable modifications.

Phosphorescent Dopant Included in Emission Layer in Organic Layer 150

The phosphorescent dopant may include an organometallic complex represented by Formula 401 below:

In Formulae 401 and 402,

M may be selected from iridium (Ir), platinum (Pt), palladium (Pd), osmium (Os), titanium (Ti), zirconium (Zr), hafnium (Hf), europium (Eu), a terbium (Tb), rhodium (Rh), and thulium (Tm),

L₄₀₁ may be a ligand represented by Formula 402, and xc1 may be 1, 2, or 3, wherein when xc1 is two or more, two or more of L₄₀₁(s) may be identical to or different from each other,

L₄₀₂ may be an organic ligand, and xc2 may be an integer from 0 to 4, wherein when xc2 is two or more, two or more of L₄₀₂(s) may be identical to or different from each other,

X₄₀₁ to X₄₀₄ may each independently be nitrogen or carbon,

X₄₀₁ and X₄₀₃ may be linked via a single bond or a double bond, and X₄₀₂ and X₄₀₄ may be linked via a single bond or a double bond,

A₄₀₁ and A₄₀₂ may each independently be a C₅-C₆₀ carbocyclic group or a C₁-C₆₀ heterocyclic group,

X₄₀₅ may be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₁)-*′, *—C(Q₄₁₁)(Q₄₁₂)-*′, *—C(Q₄₁₁)=C(Q₄₁₂)-*, *—C(Q₄₁₁)=*′, or *═C═*′, wherein Q₄₁₁ and Q₄₁₂ may be hydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group,

X₄₀₆ may be a single bond, O, or S,

R₄₀₁ and R₄₀₂ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a substituted or unsubstituted C₁-C₂₀ alkyl group, a substituted or unsubstituted C₁-C₂₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂), and Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a C₆-C₂₀ aryl group, and a C₁-C₂₀ heteroaryl group,

xc11 and xc12 may each independently be an integer from 0 to 10, and

* and *′ in Formula 402 each indicate a binding site to a M in Formula 401.

In one or more embodiments, A₄₀₁ and A₄₀₂ in Formula 402 may each independently be selected from a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, an indene group, a pyrrole group, a thiophene group, a furan group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a quinoxaline group, a quinazoline group, a carbazole group, a benzimidazole group, a benzofuran group, a benzothiophene group, an isobenzothiophene group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a dibenzofuran group, and a dibenzothiophene group.

In one or more embodiments, in Formula 402, i) X₄₀₁ may be nitrogen, and X₄₀₂ may be carbon, or ii) both X₄₀₁ and X₄₀₂ may be nitrogen.

In one or more embodiments, R₄₀₁ and R₄₀₂ in Formula 402 may each independently be selected from:

hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, and a C₁-C₂₀ alkoxy group;

a C₁-C₂₀ alkyl group and a C₁-C₂₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a phenyl group, a naphthyl group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, and a norbornenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group;

a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, an adamantanyl group, a norbornanyl group, a norbornenyl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a dibenzofuranyl group, and a dibenzothiophenyl group; and

—Si(Q₄₀₁)(Q₄₀₂)(Q₄₀₃), —N(Q₄₀₁)(Q₄₀₂), —B(Q₄₀₁)(Q₄₀₂), —C(═O)(Q₄₀₁), —S(═O)₂(Q₄₀₁), and —P(═O)(Q₄₀₁)(Q₄₀₂),

wherein Q₄₀₁ to Q₄₀₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, and a naphthyl group, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, when xc1 in Formula 401 is two or more, two A₄₀₁(s) in two or more L₄₀₁(s) may optionally be linked to each other via X₄₀₇, which is a linking group, and/or two A₄₀₂(s) may optionally be linked to each other via X₄₀₈, which is a linking group (see e.g., Compounds PD1 to PD4 and PD7). X₄₀₇ and X₄₀₈ may each independently be a single bond, *—O—*′, *—S—*′, *—C(═O)—*′, *—N(Q₄₁₃)-*′, *—C(Q₄₁₃)(Q₄₁₄)-*′, or *—C(Q₄₁₃)=C(Q₄₁₄)-*′ (where Q₄₁₃ and Q₄₁₄ may each independently be hydrogen, deuterium, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group), but embodiments of the present disclosure are not limited thereto.

L₄₀₂ in Formula 401 may be a monovalent, divalent, or trivalent organic ligand. For example, L₄₀₂ may be selected from halogen, diketone (for example, acetylacetonate), carboxylic acid (for example, picolinate), —C(═O), isonitrile, —CN, and a phosphorus-containing material (for example, phosphine and/or phosphite), but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the phosphorescent dopant may be selected from, for example, Compounds PD1 to PD25, but embodiments of the present disclosure are not limited thereto:

Fluorescent dopant or delayed fluorescent dopant in emission layer

The fluorescent dopant and/or the delayed fluorescent dopant may include the first compound.

In some embodiments, the fluorescent dopant and/or the delayed fluorescent dopant may include an arylamine compound or a styrylamine compound.

The fluorescent dopant and/or the delayed fluorescent dopant may include a compound represented by Formula 501:

In Formula 501,

Ar₅₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₅₀₁ to L₅₀₃ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xd1 to xd3 may each independently be an integer from 0 to 3,

R₅₀₁ and R₅₀₂ may each independently be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, and

xd4 may be an integer from 1 to 6.

In one or more embodiments, Ar₅₀₁ in Formula 501 may be selected from:

a naphthalene group, a heptalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, and an indenophenanthrene group; and

a naphthalene group, a heptalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, and an indenophenanthrene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In one or more embodiments, L₅₀₁ to L₅₀₃ in Formula 501 may each independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, and a pyridinylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group.

In one or more embodiments, R₅₀₁ and R₅₀₂ in Formula 501 may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group; and

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃),

wherein Q₃₁ to Q₃₃ may be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In one or more embodiments, xd4 in Formula 501 may be 2, but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, the fluorescent dopant and/or the delayed fluorescent dopant may be selected from Compounds FD1 to FD22:

In one or more embodiments, the fluorescent dopant and/or the delayed fluorescent dopant may be selected from the following compounds, but embodiments of the present disclosure are not limited thereto:

The fluorescent dopant and/or the delayed fluorescent dopant may include a compound represented by Formula 701:

In Formulae 701 and 702,

Y₇₀₁ and Y₇₀₂ may each independently be selected from a single bond, —O—, —S—, —C(R₇₀₄)(R₇₀₅)—, —N(R₇₀₄)—, Si(R₇₀₄)(R₇₀₅)—, —C(═O)₂—, —S(═O)₂—, —B(R₇₀₄)—, —P(R₇₀₅)—, and —P(═O)(R₇₀₄)(R₇₀₅)—,

X₇₀₁ may be N, B, or P,

A₇₀₁ to A₇₀₃ may each independently be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

L₇₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

b701 may be an integer from 0 to 3,

Ar₇₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

R₇₀₁ to R₇₀₅ may each independently be selected from a group represented by Formula 702, hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted C₁-C₆₀ heteroaryloxy group, a substituted or unsubstituted C₁-C₆₀ heteroarylthio group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₇₀₁)(Q₇₀₂)(Q₇₀₃), —N(Q₇₀₁)(Q₇₀₂), —B(Q₇₀₁)(Q₇₀₂), —C(═O)(Q₇₀₁), —S(═O)₂(Q₇₀₁), and —P(═O)(Q₇₀₁)(Q₇₀₂),

Q₇₀₁ to Q₇₀₃ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a carbazolyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a triazinyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a biphenyl group, and a terphenyl group, and

a701 to a703 may each independently be an integer from 1 to 6.

In one or more embodiments, A₇₀₁ to A₇₀₃ and Ar₇₀₁ in Formulae 701 and 702 may each independently be selected from:

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group; and

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂).

In one or more embodiments, L₇₀₁ in Formula 702 may be selected from:

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group; and

a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂).

In one or more embodiments, R₇₀₁ to R₇₀₅ in Formula 701 may each independently be selected from:

a group represented by Formula 702, hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₂₀ alkyl group, a C₂-C₂₀ alkenyl group, and a C₂-C₂₀ alkynyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, and a pyridinyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃); and

a C₁-C₂₀ alkyl group, a C₂-C₂₀ alkenyl group, and a C₂-C₂₀ alkynyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, and —Si(Q₃₁)(Q₃₂)(Q₃₃), and

Q₃₁ to Q₃₃ may be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

The fluorescent dopant and/or the delayed fluorescent dopant may be selected from the following compounds, but embodiments of the present disclosure are not limited thereto:

Electron Transport Region in Organic Layer 150

The electron transport region may have i) a single-layered structure including (e.g., consisting of) a single layer including a single material, ii) a single-layered structure including (e.g., consisting of) a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron transport region may include at least one selected from a buffer layer, a hole blocking layer, an electron control layer, an electron transport layer, and an electron injection layer, but embodiments of the present disclosure are not limited thereto.

For example, the electron transport region may have an electron transport layer/electron injection layer structure, a hole blocking layer/electron transport layer/electron injection layer structure, an electron control layer/electron transport layer/electron injection layer structure, or a buffer layer/electron transport layer/electron injection layer structure, wherein for each structure, constituting layers are sequentially stacked from an emission layer. However, embodiments of the structure of the electron transport region are not limited thereto.

The electron transport region (for example, a buffer layer, a hole blocking layer, an electron control layer, and/or an electron transport layer in the electron transport region) may include a metal-free compound containing at least one π-electron-deficient nitrogen-containing ring.

The “π-electron-deficient nitrogen-containing ring” as used herein may refer to a C₁-C₆₀ heterocyclic group having at least one *—N═*′ moiety as a ring-forming moiety.

For example, the “π-electron-deficient nitrogen-containing ring” may be i) a 5-membered to 7-membered heteromonocyclic group having at least one *—N═*′ moiety, ii) a heteropolycyclic group in which two or more 5-membered to 7-membered heteromonocyclic groups, each having at least one *—N═*′ moiety, are condensed with each other, or iii) a heteropolycyclic group in which at least one of 5-membered to 7-membered heteromonocyclic groups, each having at least one *—N═*′ moiety, is condensed with at least one C₅-C₆₀ carbocyclic group.

Examples of the r-electron-deficient nitrogen-containing ring may include an imidazole ring, a pyrazole ring, a thiazole ring, an isothiazole ring, an oxazole ring, an isoxazole ring, a pyridine ring, a pyrazine ring, a pyrimidine ring, a pyridazine ring, an indazole ring, a purine ring, a quinoline ring, an isoquinoline ring, a benzoquinoline ring, a phthalazine ring, a naphthyridine ring, a quinoxaline ring, a quinazoline ring, a cinnoline ring, a phenanthridine ring, an acridine ring, a phenanthroline ring, a phenazine ring, a benzimidazole ring, an isobenzothiazole ring, a benzoxazole ring, an isobenzoxazole ring, a triazole ring, a tetrazole ring, an oxadiazole ring, a triazine ring, a thiadiazole ring, an imidazopyridine ring, an imidazopyrimidine ring, and an azacarbazole ring, but are not limited thereto.

For example, the electron transport region may include a compound represented by Formula 601 below:

[Ar₆₀₁]_(xe11)-[(L₆₀₁)_(xe1)-R₆₀₁]_(xe21).  Formula 601

In Formula 601,

Ar₆₀₁ may be a substituted or unsubstituted C₅-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group,

xe11 may be 1, 2, or 3,

L₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkylene group, a substituted or unsubstituted C₃-C₁₀ cycloalkenylene group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenylene group, a substituted or unsubstituted C₆-C₆₀ arylene group, a substituted or unsubstituted C₁-C₆₀ heteroarylene group, a substituted or unsubstituted divalent non-aromatic condensed polycyclic group, and a substituted or unsubstituted divalent non-aromatic condensed heteropolycyclic group,

xe1 may be an integer from 0 to 5,

R₆₀₁ may be selected from a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₆₀₁)(Q₆₀₂)(Q₆₀₃), —C(═O)(Q₆₀₁), —S(═O)₂(Q₆₀₁), and —P(═O)(Q₆₀₁)(Q₆₀₂),

Q₆₀₁ to Q₆₀₃ may each independently be a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, and

xe21 may be an integer from 1 to 5.

In one or more embodiments, at least one of Ar₆₀₁(s) in the number of xe11 or R₆₀₁(s) in the number of xe21 may include the π-electron-deficient nitrogen-containing ring.

In one or more embodiments, Ar₆₀₁ in Formula 601 may be selected from:

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, and an azacarbazole group; and

a benzene group, a naphthalene group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, an indenoanthracene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, an indazole group, a purine group, a quinoline group, an isoquinoline group, a benzoquinoline group, a phthalazine group, a naphthyridine group, a quinoxaline group, a quinazoline group, a cinnoline group, a phenanthridine group, an acridine group, a phenanthroline group, a phenazine group, a benzimidazole group, an isobenzothiazole group, a benzoxazole group, an isobenzoxazole group, a triazole group, a tetrazole group, an oxadiazole group, a triazine group, a thiadiazole group, an imidazopyridine group, an imidazopyrimidine group, and an azacarbazole group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₃₁ to Q₃₃ may each independently be selected from a C₁-C₁₀ alkyl group, a C₁-C₁₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

When xe11 in Formula 601 is 2 or more, two or more Ar₆₀₁(s) may be linked to each other via a single bond.

In one or more embodiments, Ar₆₀₁ in Formula 601 may be an anthracene group.

In one or more embodiments, the compound represented by Formula 601 may be represented by Formula 601-1:

In Formula 601-1,

X₆₁₄ may be N or C(R₆₁₄), X₆₁₅ may be N or C(R₆₁₅), X₆₁₆ may be N or C(R₆₁₆), and at least one of X₆₁₄ to X₆₁₆ may be N,

L₆₁₁ to L₆₁₃ may each independently be the same as described in connection with L₆₀₁,

xe611 to xe613 may each independently be the same as described in connection with xe1,

R₆₁₁ to R₆₁₃ may each independently be the same as described in connection with R₆₀₁, and

R₆₁₄ to R₆₁₆ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group.

In one or more embodiments, L₆₀₁ and L₆₁₁ to L₆₁₃ in Formulae 601 and 601-1 may each independently be selected from:

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group; and

a phenylene group, a naphthylene group, a fluorenylene group, a spiro-bifluorenylene group, a benzofluorenylene group, a dibenzofluorenylene group, a phenanthrenylene group, an anthracenylene group, a fluoranthenylene group, a triphenylenylene group, a pyrenylene group, a chrysenylene group, a perylenylene group, a pentaphenylene group, a hexacenylene group, a pentacenylene group, a thiophenylene group, a furanylene group, a carbazolylene group, an indolylene group, an isoindolylene group, a benzofuranylene group, a benzothiophenylene group, a dibenzofuranylene group, a dibenzothiophenylene group, a benzocarbazolylene group, a dibenzocarbazolylene group, a dibenzosilolylene group, a pyridinylene group, an imidazolylene group, a pyrazolylene group, a thiazolylene group, an isothiazolylene group, an oxazolylene group, an isoxazolylene group, a thiadiazolylene group, an oxadiazolylene group, a pyrazinylene group, a pyrimidinylene group, a pyridazinylene group, a triazinylene group, a quinolinylene group, an isoquinolinylene group, a benzoquinolinylene group, a phthalazinylene group, a naphthyridinylene group, a quinoxalinylene group, a quinazolinylene group, a cinnolinylene group, a phenanthridinylene group, an acridinylene group, a phenanthrolinylene group, a phenazinylene group, a benzimidazolylene group, an isobenzothiazolylene group, a benzoxazolylene group, an isobenzoxazolylene group, a triazolylene group, a tetrazolylene group, an imidazopyridinylene group, an imidazopyrimidinylene group, and an azacarbazolylene group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group,

but embodiments of the present disclosure are not limited thereto.

In one or more embodiments, xe1 and xe611 to xe613 in Formulae 601 and 601-1 may each independently be 0, 1, or 2.

In one or more embodiments, R₆₀₁ and R₆₁₁ to R₆₁₃ in Formulae 601 and 601-1 may each independently be selected from:

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group;

a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a triphenylenyl group, a pyrenyl group, a chrysenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a thiophenyl group, a furanyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a benzocarbazolyl group, a dibenzocarbazolyl group, a dibenzosilolyl group, a pyridinyl group, an imidazolyl group, a pyrazolyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a thiadiazolyl group, an oxadiazolyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, an isoquinolinyl group, a benzoquinolinyl group, a phthalazinyl group, a naphthyridinyl group, a quinoxalinyl group, a quinazolinyl group, a cinnolinyl group, a phenanthridinyl group, an acridinyl group, a phenanthrolinyl group, a phenazinyl group, a benzimidazolyl group, an isobenzothiazolyl group, a benzoxazolyl group, an isobenzoxazolyl group, a triazolyl group, a tetrazolyl group, an imidazopyridinyl group, an imidazopyrimidinyl group, and an azacarbazolyl group; and

—S(═O)₂(Q₆₀₁) and —P(═O)(Q₆₀₁)(Q₆₀₂),

wherein Q₆₀₁ and Q₆₀₂ are the same as described above.

The electron transport region may include at least one compound selected from Compounds ET1 to ET36, but embodiments of the present disclosure are not limited thereto:

In one or more embodiments, the electron transport region may include at least one selected from 2,9-dimethyl-4,7-diphenyl-1, 10-phenanthroline (BCP), 4,7-diphenyl-1, 10-phenanthroline (Bphen), Alq₃, BAlq, 3-(biphenyl-4-yl)-5-(4-tert-butylphenyl)-4-phenyl-4H-1,2,4-triazole (TAZ), and NTAZ:

In one embodiment, the electron transport region may include a phosphine oxide-containing compound (for example, TSPO1, used in the following examples, and/or the like), but embodiments of the present disclosure are not limited thereto. In one or more embodiments, the phosphine oxide-containing compound may be used in a hole blocking layer in the electron transport region, but embodiments of the present disclosure are not limited thereto.

Thicknesses of the buffer layer, the hole blocking layer, and the electron control layer may each independently be in a range of about 20 Å to about 1,000 Å, for example, about 30 Å to about 300 Å. When the thicknesses of the buffer layer, the hole blocking layer, and the electron control layer are each independently within their respective these ranges, excellent (or improved) hole blocking characteristics and/or excellent (or improved) electron control characteristics may be obtained without a substantial increase in driving voltage.

A thickness of the electron transport layer may be in a range of about 100 Å to about 1,000 Å, for example, about 150 Å to about 500 Å. When the thickness of the electron transport layer is within the range described above, the electron transport layer may have satisfactory (or suitable) electron transport characteristics without a substantial increase in driving voltage.

The electron transport region (for example, the electron transport layer in the electron transport region) may further include, in addition to the materials described above, a metal-containing material.

The metal-containing material may include at least one selected from alkali metal complex and alkaline earth-metal complex. The alkali metal complex may include a metal ion selected from a Li ion, a Na ion, a K ion, a Rb ion, and a Cs ion, and the alkaline earth-metal complex may include a metal ion selected from a Be ion, a Mg ion, a Ca ion, a Sr ion, and a Ba ion. A ligand coordinated with the metal ion of the alkali metal complex or the alkaline earth-metal complex may each independently be selected from a hydroxy quinoline, a hydroxy isoquinoline, a hydroxy benzoquinoline, a hydroxy acridine, a hydroxy phenanthridine, a hydroxy phenyloxazole, a hydroxy phenylthiazole, a hydroxy phenyloxadiazole, a hydroxy phenylthiadiazole, a hydroxy phenylpyridine, a hydroxy phenylbenzimidazole, a hydroxy phenylbenzothiazole, a bipyridine, a phenanthroline, and a cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

For example, the metal-containing material may include a Li complex. The Li complex may include, for example, Compound ET-D1 (lithium quinolate, LiQ) and/or Compound ET-D2:

The electron transport region may include an electron injection layer that facilitates the injection of electrons from the second electrode 190. The electron injection layer may directly contact the second electrode 190.

The electron injection layer may have i) a single-layered structure including (e.g., consisting of) a single layer including (e.g., consisting of) a single material, ii) a single-layered structure including (e.g., consisting) a single layer including a plurality of different materials, or iii) a multi-layered structure having a plurality of layers including a plurality of different materials.

The electron injection layer may include an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof.

The alkali metal may be selected from Li, Na, K, Rb, and Cs. In one or more embodiments, the alkali metal may be Li, Na, or Cs. In one or more embodiments, the alkali metal may be Li or Cs, but embodiments of the present disclosure are not limited thereto.

The alkaline earth metal may be selected from Mg, Ca, Sr, and Ba.

The rare earth metal may be selected from Sc, Y, Ce, Tb, Yb, and Gd.

The alkali metal compound, the alkaline earth-metal compound, and the rare earth metal compound may each independently be selected from oxides and halides (for example, fluorides, chlorides, bromides, and/or iodides) of the alkali metal, the alkaline earth-metal, and the rare earth metal, respectively.

The alkali metal compound may be selected from alkali metal oxides (such as Li₂O, Cs₂O, and/or K₂O), and alkali metal halides (such as LiF, NaF, CsF, KF, LiI, NaI, CsI, and/or KI). In one or more embodiments, the alkali metal compound may be selected from LiF, Li₂O, NaF, LiI, NaI, CsI, and KI, but embodiments of the present disclosure are not limited thereto.

The alkaline earth-metal compound may be selected from alkaline earth-metal oxides (such as BaO, SrO, CaO, Ba_(x)Sr_(1-x)O (0<x<1), and/or Ba_(x)Ca_(1-x)O (0<x<1)). In one or more embodiments, the alkaline earth-metal compound may be selected from BaO, SrO, and CaO, but embodiments of the present disclosure are not limited thereto.

The rare earth metal compound may be selected from YbF₃, ScF₃, Sc₂O₃, Y₂O₃, Ce₂O₃, GdF₃ and TbF₃. In one or more embodiments, the rare earth metal compound may be selected from YbF₃, ScF₃, TbF₃, YbI₃, ScI₃, and TbI₃, but embodiments of the present disclosure are not limited thereto.

The alkali metal complex, the alkaline earth-metal complex, and the rare earth metal complex may respectively include a metal ion of alkali metal, alkaline earth-metal, and rare earth metal as described above, and a ligand coordinated with a metal ion of the alkali metal complex, the alkaline earth-metal complex, or the rare earth metal complex may each independently be selected from hydroxy quinoline, hydroxy isoquinoline, hydroxy benzoquinoline, hydroxy acridine, hydroxy phenanthridine, hydroxy phenyloxazole, hydroxy phenylthiazole, hydroxy phenyloxadiazole, hydroxy phenylthiadiazole, hydroxy phenylpyridine, hydroxy phenylbenzimidazole, hydroxy phenylbenzothiazole, bipyridine, phenanthroline, and cyclopentadiene, but embodiments of the present disclosure are not limited thereto.

The electron injection layer may include (e.g., may consist of) an alkali metal, an alkaline earth metal, a rare earth metal, an alkali metal compound, an alkaline earth-metal compound, a rare earth metal compound, an alkali metal complex, an alkaline earth-metal complex, a rare earth metal complex, or any combination thereof, as described above. In one or more embodiments, the electron injection layer may further include the organic material. When the electron injection layer further includes an organic material, the alkali metal, the alkaline earth metal, the rare earth metal, the alkali metal compound, the alkaline earth-metal compound, the rare earth metal compound, the alkali metal complex, the alkaline earth-metal complex, the rare earth metal complex, or any combination thereof may be homogeneously or non-homogeneously dispersed in a matrix including the organic material.

A thickness of the electron injection layer may be in a range of about 1 Å to about 100 Å, for example, about 3 Å to about 90 Å. When the thickness of the electron injection layer is within the range described above, the electron injection layer may have satisfactory (or suitable) electron injection characteristics without a substantial increase in driving voltage.

Second Electrode 190

The second electrode 190 is located on the organic layer 150 having the structure according to embodiments of the present disclosure. The second electrode 190 may be a cathode, which is an electron injection electrode, and in this regard, a material for forming the second electrode 190 may be selected from a metal, an alloy, an electrically conductive compound, and a combination thereof, which have a relatively low work function.

The second electrode 190 may include at least one selected from lithium (Li), silver (Ag), magnesium (Mg), aluminum (Al), aluminum-lithium (Al—Li), calcium (Ca), magnesium-indium (Mg—In), magnesium-silver (Mg—Ag), ITO, and IZO, but embodiments of the present disclosure are not limited thereto. The second electrode 190 may be a transmissive electrode, a semi-transmissive electrode, or a reflective electrode.

The second electrode 190 may have a single-layered structure or a multi-layered structure including two or more layers.

Description of FIGS. 2 to 4

An organic light-emitting device 20 of FIG. 2 includes a first capping layer 210, the first electrode 110, the organic layer 150, and the second electrode 190, which are sequentially stacked in this stated order, an organic light-emitting device 30 of FIG. 3 includes the first electrode 110, the organic layer 150, the second electrode 190, and a second capping layer 220, which are sequentially stacked in this stated order, and an organic light-emitting device 40 of FIG. 4 includes the first capping layer 210, the first electrode 110, the organic layer 150, the second electrode 190, and the second capping layer 220, which are sequentially stacked in this stated order.

Regarding FIGS. 2 to 4, the first electrode 110, the organic layer 150, and the second electrode 190 may be understood by referring to their respective descriptions presented in connection with FIG. 1.

In the organic layer 150 of each of the organic light-emitting devices 20 and 40, light generated in an emission layer may pass through the first electrode 110, which is a semi-transmissive electrode or a transmissive electrode, and the first capping layer 210 toward the outside, and in the organic layer 150 of each of the organic light-emitting devices 30 and 40, light generated in an emission layer may pass through the second electrode 190, which is a semi-transmissive electrode or a transmissive electrode, and the second capping layer 220 toward the outside.

The first capping layer 210 and the second capping layer 220 may increase external luminescence efficiency according to the principle of constructive interference.

The first capping layer 210 and the second capping layer 220 may each independently be an organic capping layer including an organic material, an inorganic capping layer including an inorganic material, or a composite capping layer including an organic material and an inorganic material.

For example, a refractive index with respect to a wavelength of 589 nm of at least one of the first capping layer 210 or the second capping layer 220 may be 1.6 or more.

For example, the organic light-emitting devices 20 and 40 may further include the first capping layer 210 under the first electrode 110, and a refractive index (index of refraction) with respect to a wavelength of 589 nm of the first capping layer 210 may be 1.6 or more.

For example, the organic light-emitting devices 30 and 40 may further include the second capping layer 220 above the second electrode 190, and a refractive index with respect to a wavelength of 589 nm of the second capping layer 220 may be 1.6 or more.

At least one of the first capping layer 210 or the second capping layer 220 may each independently include at least one material selected from carbocyclic compounds, heterocyclic compounds, amine-based compounds, porphyrin derivatives, phthalocyanine derivatives, naphthalocyanine derivatives, alkali metal complexes, and alkaline earth metal complexes. The carbocyclic compound, the heterocyclic compound, and the amine-based compound may each independently be optionally substituted with a substituent containing at least one element selected from O, N, S, Se, Si, F, Cl, Br, and I. In one or more embodiments, at least one of the first capping layer 210 and the second capping layer 220 may each independently include an amine-based compound.

In one or more embodiments, at least one of the first capping layer 210 and the second capping layer 220 may each independently include the compound represented by Formula 201 or the compound represented by Formula 202.

In one or more embodiments, at least one of the first capping layer 210 and the second capping layer 220 may each independently include a compound selected from Compounds HT28 to HT33 and Compounds CP1 to CP5, but embodiments of the present disclosure are not limited thereto.

Hereinbefore, the organic light-emitting device according to one or more embodiments has been described in connection with FIGS. 1-4. However, embodiments of the present disclosure are not limited thereto.

Layers constituting the hole transport region, the emission layer, and layers constituting the electron transport region may each independently be formed in a certain region by using one or more suitable methods selected from vacuum deposition, spin coating, casting, Langmuir-Blodgett (LB) deposition, ink-jet printing, laser-printing, and laser-induced thermal imaging.

When any of the layers constituting the hole transport region, the emission layer, and layers constituting the electron transport region are formed by vacuum deposition, the deposition may be performed at a deposition temperature of about 100° C. to about 500° C., a vacuum degree of about 10⁻⁸ torr to about 10⁻³ torr, and a deposition speed of about 0.01 Å/sec to about 100 Å/sec by taking into account a material to be included in a layer to be formed and the structure of a layer to be formed.

When any of the layers constituting the hole transport region, an emission layer, and layers constituting the electron transport region are formed by spin coating, the spin coating may be performed at a coating speed of about 2,000 rpm to about 5,000 rpm and at a heat treatment temperature of about 80° C. to 200° C. by taking into account a material to be included in a layer to be formed and the structure of a layer to be formed.

Full-Color Organic Light-Emitting Device

FIG. 5 is a schematic cross-sectional view of an organic light-emitting device 50 according to one or more embodiments.

As the substrate 501, the substrate as described above may be used. In some embodiments, the organic light-emitting device 50 may further include, between the substrate 501 and pixel electrodes 511, 512, and 513 (also referred to as a first pixel electrode 511, a second pixel electrode 512, and a third pixel electrode 513, respectively), a thin-film transistor including a source electrode, a drain electrode, and an active layer, a buffer layer, and an organic insulating layer.

The organic light-emitting device 50 of FIG. 5 includes a first emission area, a second emission area, and a third emission area.

The organic light-emitting device 50 includes the first pixel electrode 511, the second pixel electrode 512, and the third pixel electrode 513, arranged in the first emission area, the second emission area, and the third emission area, respectively.

The first pixel electrode 511, the second pixel electrode 512, and the third pixel electrode 513 are the same as described in connection with the first electrode 110 in the present specification.

The first pixel electrode 511, the second pixel electrode 512, and the third pixel electrode 513 may each be electrically connected to any one of the source electrode and the drain electrode of the thin-film transistor.

The organic light-emitting device 50 includes an opposite electrode 590 facing the first pixel electrode 511, the second pixel electrode 512, and the third pixel electrode 513.

An organic layer is arranged between the opposite electrode 590 and the first pixel electrode 511, the second pixel electrode 512, and the third pixel electrode 513. The organic layer includes a hole injection layer 520, a hole transport layer 530, emission layers 551, 552, and 553 (also referred to as a first emission layer 551, a second emission layer 552, and a third emission layer 553 respectively), an electron transport layer 560, and an electron injection layer 570. In some embodiments, an emission auxiliary layer may be arranged between the hole transport layer 530 and the first emission layer 551, between the hole transport layer 530 and the second emission layer 552, and/or between the hole transport layer 530 and the third emission layer 553.

A pixel defining film 505 may be formed at an edge portion of the first pixel electrode 511, the second pixel electrode 512, and the third pixel electrode 513. The pixel defining film 505 defines a pixel area and may include various suitable organic insulation materials (for example, a silicon-based material), inorganic insulation materials, and/or organic/inorganic composite insulation materials.

The hole injection layer 520 and the hole transport layer 530 are sequentially formed as common layers on the first pixel electrode 511, the second pixel electrode 512, and the third pixel electrode 513.

The hole injection layer 520 and the hole transport layer 530 are the same as described in connection with the organic light-emitting device 10 in the present specification.

The first emission layer 551 arranged to correspond to the first emission area and to emit first-color light, the second emission layer 552 arranged to correspond to the second emission area and to emit second-color light, and the third emission layer 553 arranged to correspond to the third emission area and to emit third-color light are formed on the hole transport layer 530.

An electron transport layer 560, an electron injection layer 570, and the opposite electrode 590 are sequentially formed, on the hole transport layer 530, as common layers for all of the first emission area, the second emission area, and the third emission area.

The electron transport layer 560 and the electron injection layer 570 are the same as described in connection with the organic light-emitting device 10 in the present specification. The opposite electrode 590 is the same as described in connection with the second electrode 190 in the present specification.

A capping layer 600 is arranged on the opposite electrode 590. A material that may be used for the capping layer 600 may include an organic material and/or an inorganic material. In one or more embodiments, the capping layer 600 may include a compound selected from Compounds HT28 to HT33 and Compounds CP1 to CP5, but embodiments of the present disclosure are not limited thereto.

In addition to functioning to protect the organic light-emitting device 50, the capping layer 600 may help light generated from the organic light-emitting device 50 to be efficiently (or suitably) emitted.

A maximum luminescence wavelength of the first-color light and a maximum luminescence wavelength of the second-color light may each be greater than a maximum luminescence wavelength of the third-color light.

The first-color light may be red light, the second-color light may be green light, and the third-color light may be blue light, but embodiments of the present disclosure are not limited thereto. Accordingly, the organic light-emitting device 50 may emit full color light. The first-color light, the second-color light, and the third-color light are not limited to red light, green light, and blue light, respectively, as long as mixed light thereof is a combination that may become white light.

In one or more embodiments, a maximum luminescence wavelength of the first-color light may be from about 620 nm to about 750 nm, a maximum luminescence wavelength of the second-color light may be from about 495 nm to about 570 nm, and a maximum luminescence wavelength of the third-color light may be from about 430 nm to about 495 nm, but embodiments of the present disclosure are not limited thereto.

At least one of the first emission layer 551, the second emission layer 552, or the third emission layer 553 includes at least one first compound, and the first compound and the dopant are the same as described above.

In one or more embodiments, one of the first emission layer 551, the second emission layer 552, and the third emission layer 553 may include the first compound, the remaining ones of the first emission layer 551, the second emission layer 552, and the third emission layer 553 may include a compound different from the first compound.

In one or more embodiments, two of the first emission layer 551, the second emission layer 552, and the third emission layer 553 may include the first compound, the remaining one of the first emission layer 551, the second emission layer 552, and the third emission layer 553 may include a compound different from the first compound.

In one or more embodiments, three of the first emission layer 551, the second emission layer 552, and the third emission layer 553 may include the first compound.

Here, the compound different from the first compound may be a compound having a formula different from that of the first compound, or may be a compound that has the same formula structure as that of the first compound and has a structure in which ¹⁵N is substituted with (e.g., substituted for) ¹⁴N.

In one or more embodiments, an emission layer including the first compound from among the first emission layer 551, the second emission layer 552, and the third emission layer 553 may include a compound having the same formula structure as that of the first compound included in the first emission layer 551, and may not include a compound having a structure in which ¹⁵N is substituted with (e.g., substituted for)¹⁴N.

Although FIG. 5 illustrates the organic light-emitting device 50 including all of the pixel defining film 505, the hole injection layer 520, the hole transport layer 530, the electron transport layer 560, and the electron injection layer 570, at least one of the described layers may be omitted.

Description of FIG. 6

FIG. 6 is a schematic cross-sectional view of an organic light-emitting device 60 according to another embodiment.

Referring to FIG. 6, the organic light-emitting device 60 includes: a first electrode 110; a second electrode 190 facing the first electrode; and m emission units ELU between the first electrode 110 and the second electrode 190, wherein m is an integer of 2 or more, the m emission units ELU each include an organic layer including an emission layer, at least one of the m emission layers included in the m emission units ELU includes at least one first compound, and the first compound includes at least one ¹⁵N and is represented by one of Formula 1-1, Formula 1-2, Formulae 2-1 to 2-3, or Formula 3.

The first electrode 110, the second electrode 190, the emission layer, the organic layer, and the first compound is the same as described in the present specification.

The organic light-emitting device 60 includes m−1 charge generating unit(s) CGU between adjacent emission units ELU among the m emission units ELU. The m emission units ELU may include a first emission units ELU1 to m^(th) emission unit ELU(m).

In some embodiments, an m−1^(th) charge generating unit is between an m^(th) emission unit and an m−1^(th) emission unit. In one or more embodiments, when m is 2, a first electrode, a first emission unit, a first charge generating unit, a second emission unit and a second electrode are sequentially arranged. In one or more embodiments, when m is 3, a first electrode, a first emission unit, a first charge generating unit, a second emission unit, a second charge generating unit, a third emission unit and a second electrode are sequentially arranged.

At least one of the charge generating unit(s) necessarily includes an interlayer between an n-type charge generation layer and a p-type charge generation layer. For example, at least one of the charge generating unit(s) includes: an n-type charge generation layer; a p-type charge generation layer; and an interlayer between the n-type charge generation layer and the p-type charge generation layer.

The n-type charge generation layer, the p-type charge generation layer, and the interlayer may each independently include any of materials included in the organic layer in the present specification.

Display Apparatus

The organic light-emitting device may be included in a display apparatus including a thin-film transistor. The thin-film transistor may include a source electrode, a drain electrode, and an active layer, wherein any one of the source electrode or the drain electrode may be electrically connected to a first electrode of an organic light-emitting device.

The thin-film transistor may further include a gate electrode, a gate insulating film, and/or the like.

The active layer may include crystalline silicon, amorphous silicon, an organic semiconductor, an oxide semiconductor, and/or the like, but embodiments of the present disclosure are not limited thereto.

The display apparatus may further include a sealing portion for sealing an organic light-emitting device. The sealing portion may allow an image from an organic light-emitting device to be implemented (e.g., displayed), and may block or reduce ambient air and/or moisture that may otherwise penetrate the organic light-emitting device. The sealing portion may be a sealing substrate including a transparent glass or a plastic substrate. The sealing portion may be a thin-film encapsulation layer including a plurality of organic layers and/or a plurality of inorganic layers. When the sealing portion is a thin-film encapsulation layer, the entire flat display apparatus may be flexible.

General Definition of Substituents

The term “C₁-C₆₀ alkyl group” as used herein refers to a linear or branched aliphatic hydrocarbon monovalent group having 1 to 60 carbon atoms, preferably C₁-C₂₀ alkyl group or C₁-C₁₀ alkyl group, and non-limiting examples thereof include a methyl group, an ethyl group, a propyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, an isoamyl group, and a hexyl group. The term “C₁-C₆₀ alkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₆₀ alkyl group.

The term “C₂-C₆₀ alkenyl group” as used herein refers to a hydrocarbon group having at least one carbon-carbon double bond in the middle and/or at either terminus of the C₂-C₆₀ alkyl group, and non-limiting examples thereof include an ethenyl group, a propenyl group, and a butenyl group. The term “C₂-C₆₀ alkenylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀ alkenyl group.

The term “C₂-C₆₀ alkynyl group” as used herein refers to a hydrocarbon group having at least one carbon-carbon triple bond in the middle and/or at either terminus of the C₂-C₆₀ alkyl group, and non-limiting examples thereof include an ethynyl group and a propynyl group. The term “C₂-C₆₀ alkynylene group” as used herein refers to a divalent group having the same structure as the C₂-C₆₀ alkynyl group.

The term “C₁-C₆₀ alkoxy group” as used herein refers to a monovalent group represented by —OA₁₀₁ (wherein A₁₀₁ is the C₁-C₆₀ alkyl group), preferably C₁-C₂₀ alkoxy group, and non-limiting examples thereof include a methoxy group, an ethoxy group, and an isopropyloxy group.

The term “C₃-C₁₀ cycloalkyl group” as used herein refers to a monovalent saturated hydrocarbon monocyclic group having 3 to 10 carbon atoms, and non-limiting examples thereof include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, and a cycloheptyl group. The term “C₃-C₁₀ cycloalkylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀ cycloalkyl group.

The term “C₁-C₁₀ heterocycloalkyl group” as used herein refers to a monovalent monocyclic group having at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, and 1 to 10 carbon atoms as the remaining ring-forming atoms, and non-limiting examples thereof include a 1,2,3,4-oxatriazolidinyl group, a tetrahydrofuranyl group, and a tetrahydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkylene group” as used herein refers to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkyl group.

The term C₃-C₁₀ cycloalkenyl group used herein refers to a monovalent monocyclic group that has 3 to 10 carbon atoms and at least one carbon-carbon double bond in the ring thereof and no aromaticity, and non-limiting examples thereof include a cyclopentenyl group, a cyclohexenyl group, and a cycloheptenyl group. The term “C₃-C₁₀ cycloalkenylene group” as used herein refers to a divalent group having the same structure as the C₃-C₁₀ cycloalkenyl group.

The term “C₁-C₁₀ heterocycloalkenyl group” as used herein refers to a monovalent monocyclic group that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, 1 to 10 carbon atoms as the remaining ring-forming atoms, and at least one double bond in its ring. Non-limiting examples of the C₁-C₁₀ heterocycloalkenyl group include a 4,5-dihydro-1,2,3,4-oxatriazolyl group, a 2,3-dihydrofuranyl group, and a 2,3-dihydrothiophenyl group. The term “C₁-C₁₀ heterocycloalkenylene group” as used herein refers to a divalent group having the same structure as the C₁-C₁₀ heterocycloalkenyl group.

The term “C₆-C₆₀ aryl group” as used herein refers to a monovalent group having a carbocyclic aromatic system having 6 to 60 carbon atoms. Non-limiting examples of the C₆-C₆₀ aryl group include a phenyl group, a naphthyl group, an anthracenyl group, a phenanthrenyl group, a pyrenyl group, and a chrysenyl group. The term “C₆-C₆₀ arylene group” as used herein refers to a divalent group having the same structure as the C₆-C₆₀ aryl group. When the C₆-C₆₀ aryl group and the C₆-C₆₀ arylene group each independently include two or more rings, the respective two or more rings may be fused to each other.

The term “C₁-C₆₀ heteroaryl group” as used herein refers to a monovalent group having a heterocyclic aromatic system that has at least one heteroatom selected from N, O, Si, P, and S as a ring-forming atom, in addition to 1 to 60 carbon atoms. Non-limiting examples of the C₁-C₆ heteroaryl group include a pyridinyl group, a pyrimidinyl group, a pyrazinyl group, a pyridazinyl group, a triazinyl group, a quinolinyl group, a carbazolyl group, and an isoquinolinyl group. The term “C₁-C₆₀ heteroarylene group” as used herein refers to a divalent group having the same structure as the C₁-C₆₀ heteroaryl group. When the C₁-C₆₀ heteroaryl group and the C₁-C₆ heteroarylene group each independently include two or more rings, the respective two or more rings may be condensed with each other.

The term “C₆-C₆₀ aryloxy group” as used herein refers to a monovalent group represented by —OA₁₀₂ (wherein A₁₀₂ is the C₆-C₆₀ aryl group), and the term “C₆-C₆₀ arylthio group” as used herein refers to a monovalent group represented by —SA₁₀₃ (wherein A₁₀₃ is the C₆-C₆₀ aryl group).

The term “monovalent non-aromatic condensed polycyclic group” as used herein refers to a monovalent group having two or more rings condensed with each other, only carbon atoms as ring-forming atoms (for example, having 8 to 60 carbon atoms), and non-aromaticity in its entire molecular structure (e.g., the molecular structure as a whole is non-aromatic). Non-limiting examples of the monovalent non-aromatic condensed polycyclic group include a fluorenyl group and a 1,2,3,4-tetrahydronaphthalenyl group. The term “divalent non-aromatic condensed polycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed polycyclic group.

The term “monovalent non-aromatic condensed heteropolycyclic group” as used herein refers to a monovalent group having two or more rings condensed to each other, at least one heteroatom selected from N, O, Si, P, and S, other than carbon atoms (for example, 1 to 60 carbon atoms), as a ring-forming atom, and non-aromaticity in its entire molecular structure (e.g., the molecular structure as a whole is non-aromatic). Non-limiting examples of the monovalent non-aromatic condensed heteropolycyclic group include a 1,2,3,4-tetrahydroquinolinyl group. The term “divalent non-aromatic condensed heteropolycyclic group” as used herein refers to a divalent group having the same structure as the monovalent non-aromatic condensed heteropolycyclic group.

The term “C₃-C₆₀ carbocyclic group” as used herein refers to a monocyclic or polycyclic group having 3 to 60 carbon atoms in which ring-forming atoms are carbon atoms only. The term “C₃-C₆₀ carbocyclic group” as used herein refers to an aromatic carbocyclic group or a non-aromatic carbocyclic group. The C₃-C₆₀ carbocyclic group may be a ring (such as benzene), a monovalent group (such as a phenyl group), or a divalent group (such as a phenylene group). In one or more embodiments, depending on the number of substituents connected to the C₃-C₆₀ carbocyclic group, the C₃-C₆₀ carbocyclic group may be a trivalent group or a quadrivalent group.

The term “C₁-C₆₀ heterocyclic group” as used herein refers to a group having the same structure as the C₃-C₆₀ carbocyclic group, except that as a ring-forming atom, at least one heteroatom selected from N, O, Si, P, and S is used in addition to carbon atoms (the number of carbon atoms may be in a range of 1 to 60).

In the present specification, at least one substituent of the substituted C₃-C₆₀ carbocyclic group, the substituted C₁-C₆ heterocyclic group, the substituted C₃-C₁₀ cycloalkylene group, the substituted C₁-C₁₀ heterocycloalkylene group, the substituted C₃-C₁₀ cycloalkenylene group, the substituted C₁-C₁₀ heterocycloalkenylene group, the substituted C₆-C₆₀ arylene group, the substituted C₁-C₆ heteroarylene group, the substituted divalent non-aromatic condensed polycyclic group, the substituted divalent non-aromatic condensed heteropolycyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group may be selected from:

deuterium (-D), —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆ alkoxy group;

a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂);

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group;

a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₂₁)(Q₂₂)(Q₂₃), —N(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂), and

—Si(Q₃₁)(Q₃₂)(Q₃₃), —N(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂),

wherein Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ may each independently be selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazino group, a hydrazono group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a C₁-C₆₀ alkyl group substituted with at least one selected from deuterium, —F, and a cyano group, a C₆-C₆₀ aryl group substituted with at least one selected from deuterium, —F, and a cyano group, a biphenyl group, and a terphenyl group.

The term “Ph” as used herein refers to a phenyl group, the term “Me” as used herein refers to a methyl group, the term “Et” as used herein refers to an ethyl group, the term “tert-Bu” or “Bu^(t)” as used herein refers to a tert-butyl group, and the term “OMe” as used herein refers to a methoxy group.

The term “biphenyl group” as used herein refers to “a phenyl group substituted with a phenyl group.” For example, the “biphenyl group” may be a substituted phenyl group having a C₆-C₆₀ aryl group as a substituent.

The term “terphenyl group” as used herein refers to “a phenyl group substituted with a biphenyl group”. For example, the “terphenyl group” may be a substituted phenyl group having, as a substituent, a C₆-C₆₀ aryl group substituted with a C₆-C₆₀ aryl group.

*, *′, and *″, as used herein, unless defined otherwise, each refer to a binding site to a neighboring atom in a corresponding formula.

Hereinafter, a compound according to one or more embodiments and an organic light-emitting device according to one or more embodiments will be described in more detail with reference to Synthesis Examples and Examples. The wording “B was used instead of A” used in describing Synthesis Examples refers to an identical molar equivalent of B being used in place of A.

EXAMPLES Comparative Example 1-1

As an anode, an ITO/Ag/ITO substrate (hereinafter, “ITO substrate”) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated by using isopropyl alcohol and pure water for 5 minutes each, and then cleaned by irradiation of ultraviolet rays and exposure of ozone thereto for 30 minutes. Then, the ITO substrate was provided to a vacuum deposition apparatus.

Compound m-MTDATA was vacuum-deposited on the ITO substrate to form a hole injection layer having a thickness of 110 nm, and NPB was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 10 nm.

H121 and PD11 were co-deposited on the hole transport layer at a weight ratio of 90:10 to form an emission layer having a thickness of 30 nm. Subsequently, BAlq was vacuum-deposited thereon to form a hole blocking layer having a thickness of 10 nm. Subsequently, Alq₃ and LiQ were co-deposited on the hole blocking layer at a ratio of 5:5 to form an electron transport layer having a thickness of 20 nm; LiF, which is an alkali metal halide, was deposited on the electron transport layer to form an electron injection layer having a thickness of 1 nm; and then Al was vacuum-deposited thereon to form an LiF/Al cathode having a thickness of 30 nm. HT28 was deposited on the cathode having a thickness of 60 nm to form a capping layer, thereby completing manufacture of an organic light-emitting device.

Example 1-1

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 1-1, except that Compound 2 was used instead of H121.

Comparative Example 1-2

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 1-1, except that PD13 was used instead of PD11.

Example 1-2

An organic light-emitting device was manufactured in substantially the same manner as in Example 1-1, except that PD13 was used instead of PD11.

Comparative Example 1-3

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 1-1, except that, instead of H121 and PD11, H123 and FD1 were co-deposited at a weight ratio of 98:2 to manufacture an emission layer.

Example 1-3

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 1-3, except that Compound 1 was used instead of H123.

Example 1-4

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 1-3, except that Compound 7 was used instead of FD1.

Example 1-5

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 1-3, except that Compound 1 was used instead of H123, and Compound 7 was used instead of FD1.

Comparative Example 1-4

As an anode, an ITO/Ag/ITO substrate (hereinafter, “ITO substrate”) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated by using isopropyl alcohol and pure water for 5 minutes each, and then cleaned by irradiation of ultraviolet rays and exposure of ozone thereto for 30 minutes. Then, the ITO substrate was provided to a vacuum deposition apparatus.

Compound m-MTDATA was vacuum-deposited on the ITO substrate to form a hole injection layer having a thickness of 110 nm, and NPB was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 10 nm.

Subsequently, within a red subpixel area, H121 and PD11 were co-deposited on the hole transport layer at a weight ratio of 90:10 to form a red emission layer having a thickness of 30 nm. Subsequently, within a green subpixel area, H121 and PD13 were co-deposited on the hole transport layer at a weight ratio of 90:10 to form a green emission layer having a thickness of 30 nm. Subsequently, within a blue subpixel area, H123 and FD1 were co-deposited on the hole transport layer at a weight ratio of 98:2 to form a blue emission layer having a thickness of 30 nm. Subsequently, BAlq was vacuum-deposited on the red, green, and blue emission layers to form a hole blocking layer having a thickness of 10 nm. Subsequently, Alq₃ and LiQ were co-deposited on the hole blocking layer to form an electron transport layer having a thickness of 20 nm; LiF, which is an alkali metal halide, was deposited on the electron transport layer to form an electron injection layer having a thickness of 1 nm; and then Al was vacuum-deposited thereon to form an LiF/Al cathode having a thickness of 30 nm. HT28 was deposited on the cathode to form a capping layer having a thickness of 60 nm, thereby completing manufacture of an organic light-emitting device.

Example 1-6

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 1-4, except that, in forming a red emission layer and a green emission layer, Compound 2 was used instead of H121, and in forming blue emission layer, Compound 1 was used instead of H123 and Compound 7 was used instead of FD1.

Evaluation Example 1

With respect to each of the organic light-emitting devices manufactured according to Examples 1-1 to 1-6 and Comparative Examples 1-1 to 1-4, a driving voltage (V) at 1000 cd/m², luminescence efficiency (cd/A), luminous color, and lifespan (LT97) were measured by using Keithley SMU 236 and a luminance meter PR650, and results thereof are shown in Table 1. In Table 1, the lifespan (LT97) indicates an amount of time that lapsed until luminance was 97% of initial luminance, wherein results are represented based on the lifespan of the organic light-emitting device of Comparative Example 1-1 being 100%.

TABLE 1 Driving Luminescence Composition of voltage efficiency Luminous Lifespan emission layer (V) (cd/A) color (LT₉₇) (%) Comparative H121 + PD11 5.3 19.2 Red 100% Example 1-1 Example 1-1 Compound 2 + PD11 5.3 19.2 Red 111% Comparative H121 + PD13 5.1 41.7 Green 100% Example 1-2 Example 1-2 Compound 2 + PD13 5.1 41.9 Green 113% Comparative H123 + FD1 4.2 6.3 Blue 100% Example 1-3 Example 1-3 Compound 1 + FD1 4.1 6.4 Blue 105% Example 1-4 H123 + Compound 7 4.2 6.3 Blue 102% Example 1-5 Compound 1 + Compound 7 4.2 6.4 Blue 106% Comparative H121 + PD11 / 6.0 20.2 White 100% Example 1-4 H121 + PD13 / H123 + FD1 Example 1-6 Compound 2 + PD11 / 6.0 20.5 White 111% Compound 2 + PD13 / Compound 1 + Compound 7

Referring to Table 1, it was confirmed that the organic light-emitting devices of Examples 1-1, 1-2, 1-3 to 1-5, and 1-6 have low driving voltage, high efficiency, and/or long lifespan, compared to the organic light-emitting devices of Comparative Examples 1-1, 1-2, 1-3, and 1-4.

Comparative Example 2-1

As an anode, an ITO/Ag/ITO substrate (hereinafter, referred to as “ITO substrate”) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated by using isopropyl alcohol and pure water for 5 minutes each, and then, cleaned by irradiation of ultraviolet rays and exposure of zone thereto for 30 minutes. Then, the ITO substrate was loaded onto a vacuum deposition apparatus.

Compound m-MTDATA was vacuum-deposited on the ITO substrate to form a hole injection layer having a thickness of 110 nm, and then NPB was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 10 nm.

H40, H122, and PD11 were co-deposited on the hole transport layer at a weight ratio of 45:45:10 to form an emission layer having a thickness of 30 nm. Subsequently, BAlq was vacuum-deposited thereon to form a hole blocking layer having a thickness of 10 nm. Subsequently, Alq₃ and Liq were co-deposited on the hole blocking layer to form an electron transport layer having a thickness of 20 nm; LiF, which is an alkali metal halide, was deposited on the electron transport layer to form an electron injection layer having a thickness of 1 nm; and Al was vacuum-deposited thereon to form an LiF/Al cathode having a thickness of 30 nm. HT28 was deposited on the cathode to form a capping layer having a thickness of 60 nm, thereby completing manufacture of an organic light-emitting device.

Example 2-1

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 2-1, except that Compound 4 and Compound 3 were used in the same amount instead of H40 and H122, respectively.

Comparative Example 2-2

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 2-1, except that PD13 was used instead of PD11.

Example 2-2

An organic light-emitting device was manufactured in substantially the same manner as in Example 2-1, except that Compound PD13 was used instead of Compound PD11.

Comparative Example 2-3

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 2-1, except that H124, H125, and FD1 were co-deposited at a weight ratio of 49:49:2 instead of H40, H122, and PD11, respectively.

Example 2-3

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 2-3, except that Compound 5 and Compound 6 were used instead of H124 and H125, respectively.

Example 2-4

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 2-3, except that Compound 7 was used instead of FD1.

Example 2-5

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 2-3, except that Compound 5 and Compound 6 were used instead of H124 and H125, respectively, and Compound 7 was used instead of FD1.

Comparative Example 2-4

As an anode, an ITO/Ag/ITO substrate (hereinafter, referred to as “ITO substrate”) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated by using isopropyl alcohol and pure water for 5 minutes each, and then, cleaned by irradiation of ultraviolet rays and exposure of zone thereto for 30 minutes. Then, the ITO substrate was loaded onto a vacuum deposition apparatus.

Compound m-MTDATA was vacuum-deposited on the ITO substrate to form a hole injection layer having a thickness of 110 nm, and then NPB was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 10 nm.

Subsequently, within a red subpixel area, H40, H122, and PD11 were co-deposited on the hole transport layer at a weight ratio of 45:45:10 to form a red emission layer having a thickness of 30 nm. Subsequently, within a green subpixel area, H40, H122, and PD13 were co-deposited on the hole transport layer at a weight ratio of 45:45:10 to form a green emission layer having a thickness of 30 nm. Subsequently, within a blue subpixel area, H124, H125, and FD1 were co-deposited on the hole transport layer at a weight ratio of 49:49:2 to form a blue emission layer having a thickness of 30 nm. Subsequently, BAlq was vacuum-deposited on the red, green, and blue emission layers to form a hole blocking layer having a thickness of 10 nm. Subsequently, Alq₃ and Liq were co-deposited on the hole blocking layer to form an electron transport layer having a thickness of 20 nm; LiF, which is an alkali metal halide, was deposited on the electron transport layer to form an electron injection layer having a thickness of 1 nm; and Al was vacuum-deposited thereon to form an LiF/Al cathode having a thickness of 30 nm. HT28 was deposited on the cathode to form a capping layer having a thickness of 60 nm, thereby completing manufacture of an organic light-emitting device.

Example 2-6

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 2-4, except that, in forming a red emission layer and a green emission layer, Compound 4 and Compound 3 were used in the same amount instead of H40 and H122, respectively, and in forming a blue emission area, Compound 5 and Compound 6 were used instead of H124 and H125, respectively, and Compound 7 was used instead of FD1.

Evaluation Example 2

With respect to each of the organic light-emitting devices manufactured according to Examples 2-1 to 2-6 and Comparative Examples 2-1 to 2-4, a driving voltage (V) at 1000 cd/m², luminescence efficiency (cd/A), luminous color, and lifespan (LT97) were measured using Keithley SMU 236 and a luminance meter PR650, and results thereof are shown in Table 2. In Table 2, the lifespan (LT97) indicates an amount of time that lapsed until luminance was 97% of initial luminance, wherein results are represented based on the lifespan of the organic light-emitting device of Comparative Example 2-1 being 100%.

TABLE 2 Driving Luminescence Composition of emission voltage efficiency Luminous Lifespan layer (V) (cd/A) color (LT₉₇) (%) Comparative H40 + H122 + PD11 4.9 23.4 Red 100% Example 2-1 Example 2-1 Compound4 + 4.9 23.5 Red 118% Compound 3 + PD11 Comparative H40 + H122 + PD13 4.8 53.2 Green 100% Example 2-2 Example 2-2 Compound 4 + 4.9 53.5 Green 115% Compound 3 + PD13 Comparative H124 + H125 + FD1 3.9 5.9 Blue 100% Example 2-3 Example 2-3 Compound 5 + 3.9 6.0 Blue 108% Compound 6 + FD1 Example 2-4 H124 + H125 + Compound 7 3.9 5.9 Blue 102% Example 2-5 Compound 5 + 3.9 6.0 Blue 108% Compound 6 + Compound 7 Comparative H40 + H122 + PD11 / 5.7 25.7 White 100% Example 2-4 H40 + H122 + PD13 / H123 + FD1 Example 2-6 Compound 4 + 5.8 25.9 White 115% Cornpound 3 + PD11 / Compound 4 + Compound 3 + PD13 / Compound 5 + Compound 6 + Compound 7

Referring to Table 2, it was confirmed that each of the organic light-emitting devices of Example 2-1, Example 2-2, Examples 2-3 to Example 2-5, and Example 2-6 has high efficiency and/or long lifespan, compared to the organic light-emitting devices of Comparative Example 2-1, Comparative Example 2-2, Comparative Example 2-3, and Comparative Example 2-4.

Comparative Example 3-1

As an anode, an ITO/Ag/ITO substrate (hereinafter, referred to as “ITO substrate”) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated by using isopropyl alcohol and pure water for 5 minutes each, and then, cleaned by irradiation of ultraviolet rays and exposure of zone thereto for 30 minutes. Then, the ITO substrate was loaded onto a vacuum deposition apparatus.

Compound m-MTDATA was vacuum-deposited on the ITO substrate to form a hole injection layer having a thickness of 110 nm, and then NPB was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 10 nm.

H126, H127, and PD11 were co-deposited on the hole transport layer at a weight ratio of 45:45:10 to form an emission layer having a thickness of 30 nm. Subsequently, BAlq was vacuum-deposited thereon to form a hole blocking layer having a thickness of 10 nm. Subsequently, Alq₃ and Liq were co-deposited on the hole blocking layer to form an electron transport layer having a thickness of 20 nm; LiF, which is an alkali metal halide, was deposited on the electron transport layer to form an electron injection layer having a thickness of 1 nm; and Al was vacuum-deposited thereon to form an LiF/Al cathode having a thickness of 30 nm. HT28 was deposited on the cathode to form a capping layer having a thickness of 60 nm, thereby completing manufacture of an organic light-emitting device.

Example 3-1

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 3-1, except that Compound 8 and Compound 9 were used in the same amount instead of H126 and H127, respectively.

Comparative Example 3-2

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 3-1, except that PD13 was used instead of PD11.

Example 3-2

An organic light-emitting device was manufactured in substantially the same manner as in Example 3-1, except that Compound PD13 was used instead of Compound PD11.

Comparative Example 3-3

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 3-1, except that, instead of H126, H127, and PD11, H123 and BD2-1 were co-deposited at a weight ratio of 98:2 to manufacture an emission layer.

Example 3-3

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 3-3, except that Compound 1 was used instead of H123.

Example 3-4

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 3-3, except that Compound 10 was used instead of BD2-1.

Example 3-5

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 3-3, except that Compound 1 was used instead of H123, and Compound 10 was used instead of BD2-1.

Comparative Example 3-4

As an anode, an ITO/Ag/ITO substrate (hereinafter, referred to as “ITO substrate”) was cut to a size of 50 mm×50 mm×0.7 mm, sonicated by using isopropyl alcohol and pure water for 5 minutes each, and then, cleaned by irradiation of ultraviolet rays and exposure of zone thereto for 30 minutes. Then, the ITO substrate was loaded onto a vacuum deposition apparatus.

Compound m-MTDATA was vacuum-deposited on the ITO substrate to form a hole injection layer having a thickness of 110 nm, and then NPB was vacuum-deposited on the hole injection layer to form a hole transport layer having a thickness of 10 nm.

Subsequently, within a red subpixel area, H40, H122, and PD11 were co-deposited on the hole transport layer at a weight ratio of 45:45:10 to form a red emission layer having a thickness of 30 nm. Subsequently, within a green subpixel area, H40, H122, and PD13 were co-deposited on the hole transport layer at a weight ratio of 45:45:10 to form a green emission layer having a thickness of 30 nm. Subsequently, within a blue subpixel area, H123 and BD2-1 were co-deposited on the hole transport layer at a weight ratio of 98:2 to form a blue emission layer having a thickness of 30 nm. Subsequently, BAlq was vacuum-deposited on the red, green, and blue emission layers to form a hole blocking layer having a thickness of 10 nm. Subsequently, Alq₃ and Liq were co-deposited on the hole blocking layer to form an electron transport layer having a thickness of 20 nm; LiF, which is an alkali metal halide, was deposited on the electron transport layer to form an electron injection layer having a thickness of 1 nm; and Al was vacuum-deposited thereon to form an LiF/Al cathode having a thickness of 30 nm. HT28 was deposited on the cathode to form a capping layer having a thickness of 60 nm, thereby completing manufacture of an organic light-emitting device.

Example 3-6

An organic light-emitting device was manufactured in substantially the same manner as in Comparative Example 3-4, except that, in forming a red emission layer and a green emission layer, Compound 4 and Compound 3 were used in the same amount instead of H40 and H122, respectively, and in forming a blue emission area, Compound 1 was used instead of H123, and Compound 10 was used instead of BD2-1.

Evaluation Example 3

With respect to each of the organic light-emitting devices manufactured according to Examples 3-1 to 3-6 and Comparative Examples 3-1 to 3-4, a driving voltage (V) at 1000 cd/m², luminescence efficiency (cd/A), luminous color, and lifespan (LT97) were measured using Keithley SMU 236 and a luminance meter PR650, and results thereof are shown in Table 3. In Table 3, the lifespan (LT97) indicates an amount of time that lapsed until luminance was 97% of initial luminance, wherein results are represented based on the lifespan of the organic light-emitting device of Comparative Example 3-1 being 100%.

TABLE 3 Driving Luminescence Composition of emission voltage efficiency Luminous Lifespan layer (V) (cd/A) color (LT₉₇) (%) Comparative H126 + H127 + PD11 5.2 21.4 Red 100% Example 3-1 Example 3-1 Compound 8 + 5.2 21.6 Red 112% Compound 9 + PD11 Comparative H126 + H127 + PD13 5.1 51.3 Green 100% Example 3-2 Example 3-2 Compound 8 + 5.2 51.7 Green 110% Compound 9 + PD13 Comparative H123 + BD2-1 4.4 6.7 Blue 100% Example 3-3 Example 3-3 Compound 1 + BD2-1 4.4 6.8 Blue 106% Example 3-4 H123 + Compound 10 4.4 6.8 Blue 102% Example 3-5 Compound 1 + Compound 10 4.4 6.9 Blue 106% Comparative H40 + H122 + PD11 / Example 3-4 H40 + H122 + PD13 / 6.1 24.7 White 100% H123 + BD2-1 Example 3-6 Compound 4 + 6.1 25.0 White 109% Compound 3 + PD11 / Compound 4 + Compound 3 + PD13 / Compound 1 + Compound 10

Referring to Table 3, it was confirmed that each of the organic light-emitting devices of Example 3-1, Example 3-2, Examples 3-3 to Example 3-5, and Example 3-6 has high efficiency and/or long lifespan, compared to the organic light-emitting devices of Comparative Example 3-1, Comparative Example 3-2, Comparative Example 3-3, and Comparative Example 3-4.

The organic light-emitting device includes an emission layer including a compound substituted with one or more ¹⁵N (isotopes of nitrogen), resulting in an increase in stability of the compound substituted with ¹⁵N and reduction in vibration energy, thereby having high efficiency and long lifespan.

As used herein, the terms “use,” “using,” and “used” may be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively.

In addition, the terms “substantially,” “about,” and similar terms are used as terms of approximation and not as terms of degree, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art.

Also, any numerical range recited herein is intended to include all subranges of the same numerical precision subsumed within the recited range. For example, a range of “1.0 to 10.0” is intended to include all subranges between (and including) the recited minimum value of 1.0 and the recited maximum value of 10.0, that is, having a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as, for example, 2.4 to 7.6. Any maximum numerical limitation recited herein is intended to include all lower numerical limitations subsumed therein and any minimum numerical limitation recited in this specification is intended to include all higher numerical limitations subsumed therein. Accordingly, Applicant reserves the right to amend this specification, including the claims, to expressly recite any sub-range subsumed within the ranges expressly recited herein.

It should be understood that embodiments described herein should be considered in a descriptive sense only and not for purposes of limitation. Descriptions of features or aspects within each embodiment should typically be considered as available for other similar features or aspects in other embodiments. While one or more embodiments have been described with reference to the figures, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the following claims and their equivalents. 

What is claimed is:
 1. An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode, the organic layer comprising an emission layer that comprises a first emission layer, a second emission layer, and a third emission layer, wherein at least one of the first emission layer, the second emission layer, or the third emission layer comprises at least one first compound, and the first compound includes at least one ¹⁵N and is represented by one of Formula 1-1, Formula 1-2, Formula 2-1 to Formula 2-3, and Formula 3:

and wherein, in Formulae 1-1, 1-2, 2-1 to 2-3, and 3, N* is ¹⁵N, and N*¹ and N*² are each independently ¹⁴N or ¹⁵N, wherein at least one of N*¹ or N*² is ¹⁵N, A₂₁ to A₂₄ and A₃₁ to A₃₃ are each independently selected from a C₃-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclic group, A₃₁ and A₃₂ are optionally linked to each other via a first linking group, X₂₁ is O, S, or N*-[(L₂₄)_(a24)-Ar₂₄], Y₂₁ and Y₂₂ are each independently a single bond, *—O—*′, *—S—*′, *—N*′(R₂₅)—*′, *—C(R₂₅)(R₂₆)—*′, *—Si(R₂₅)(R₂₆)*′, or *—C(R₂₅)═C(R₂₆)—*′, c21 and c22 are each independently an integer from 1 to 3, X₃₁ is B, P, P(═O), P(═S), Ga, As, Si(R₂₇), or Ge(R₂₇), L₁₁ to L₁₄, L₂₁ to L₂₄, and L₃₁ to L₃₅ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, L₁₅ is *—O—*′, *—S—*′, *—Se—*′, *—N*′(Ar₁₅)*′, a substituted or unsubstituted C₃-C₆₀ carbocyclic group, or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, a11 to a14, a21 to a24, and a31 to a35 are each independently an integer from 0 to 5, a15 is an integer from 1 to 10, Ar₁₁ to Ar₁₅, Ar₂₁ to Ar₂₄, and Ar₃₁ to Ar₃₃ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, b21, b22, and b31 to b33 are each independently an integer from 0 to 10, R₂₁ to R₂₇ and R₃₁ to R₃₅ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N*(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), d21 to d24 and d31 to d33 are each independently an integer from 0 to 10, at least one substituent of the substituted C₃-C₃₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆₀ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆₀ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —O(Q₁₁), —S(Q₁₁), —Si(Q₁₁)(Q₁₂)(Q₁₃), —N*′(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —P(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —O(Q₂₁), —S(Q₂₁), —Si(Q₂₁)(Q₂₂)(Q₂₃), —N*′(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —P(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and —O(Q₃₁), —S(Q₃₁), —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —P(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a C₁-C₆₀ alkyl group that is substituted with at least one selected from deuterium, —F, a cyano group, a C₁-C₆ alkyl group, a phenyl group, and a biphenyl group, and a C₆-C₆₀ aryl group that is substituted with at least one selected from deuterium, —F, a cyano group, a C₁-C₁₀ alkyl group, a phenyl group, and a biphenyl group, a nitrogen atom in the cyano group, the nitro group, the amino group, the amidino group, the hydrazine group, and the hydrazone group is ¹⁴N or ¹⁵N, N*′ is ¹⁴N or ¹⁵N, and when a heteroatom in the C₁-C₆ heterocyclic group, the C₁-C₁₀ heterocycloalkyl group, the C₁-C₁₀ heterocycloalkenyl group, the C₁-C₆₀ heteroaryl group, and the monovalent non-aromatic condensed heteropolycyclic group is each independently a nitrogen atom, the nitrogen atom is ¹⁴N or ¹⁵N, wherein * and *′ each indicate a binding site to a neighboring atom in addition to *′ in N*′.
 2. The organic light-emitting device of claim 1, wherein N*¹ and N*² are ¹⁵N.
 3. The organic light-emitting device of claim 1, wherein A₂₁ to A₂₄ and A₃₁ to A₃₃ are each independently: a benzene group, a naphthalene group, an anthracene group, a phenanthrene group, a triphenylene group, a pyrene group, a chrysene group, a cyclopentadiene group, a 1,2,3,4-tetrahydronaphthalene group, a thiophene group, a furan group, a borole group, a silole group, a germole group, an indole group, a benzoborole group, a benzophosphole group, an indene group, a benzosilole group, a benzogermole group, a benzothiophene group, a benzoselenophene group, a benzofuran group, a carbazole group, a dibenzoborole group, a dibenzophosphole group, a fluorene group, a spiro-bifluorene group, a benzofluorene group, a dibenzofluorene group, a fluoranthene group, a perylene group, a benzocarbazole group, a dibenzocarbazole group, a dibenzosilole group, a dibenzogermole group, a dibenzothiophene group, a dibenzoselenophene group, a dibenzofuran group, a naphthofuran group, a benzonaphthofuran group, a dinaphthofuran group, a naphthothiophene group, a benzonaphthothiophene group, a dinaphthothiophene group, a dibenzothiophene 5-oxide group, a 9H-fluorene-9-one group, a dibenzothiophene 5,5-dioxide group, an azaindole group, an azabenzoborole group, an azabenzophosphole group, an azaindene group, an azabenzosilole group, an azabenzogermole group, an azabenzothiophene group, an azabenzoselenophene group, an azabenzofuran group, an azacarbazole group, an azadibenzoborole group, an azadibenzophosphole group, an azafluorene group, an azadibenzosilole group, an azadibenzogermole group, an azadibenzothiophene group, an azadibenzoselenophene group, an azadibenzofuran group, an azadibenzothiophene 5-oxide group, an aza-9H-fluorene-9-one group, an azadibenzothiophene 5,5-dioxide group, a pyridine group, a pyrimidine group, a pyrazine group, a pyridazine group, a triazine group, a quinoline group, an isoquinoline group, a quinoxaline group, a quinazoline group, a phenanthroline group, a pyrrole group, a pyrazole group, an imidazole group, a triazole group, an oxazole group, an isoxazole group, a thiazole group, an isothiazole group, an oxadiazole group, a thiadiazole group, a benzopyrazole group, a benzimidazole group, a benzoxazole group, a benzothiazole group, a benzoxadiazole group, a benzothiadiazole group, a 5,6,7,8-tetrahydroisoquinoline group, or a 5,6,7,8-tetrahydroquinoline group.
 4. The organic light-emitting device of claim 1, wherein X₃₁ is B.
 5. The organic light-emitting device of claim 1, wherein L₁₁ to L₁₄, L₂₁ to L₂₄, and L₃₁ to L₃₅ are each independently selected from: a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group; a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*′(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂), L₁₅ is selected from: *—O—*′, *—S—*′, *—N*′(Ar₁₅)—*′, a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group; and a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*′(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂), Ar₁₅ is a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, and Q₃₁ to Q₃₃ are each independently selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group.
 6. The organic light-emitting device of claim 1, wherein Ar₁₁ to Ar₁₅, Ar₂₁ to Ar₂₄, and Ar₃₁ to Ar₃₃ are each independently selected from: a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group; and a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, a terphenyl group, a pentalenyl group, an indenyl group, a naphthyl group, an azulenyl group, a heptalenyl group, an indacenyl group, an acenaphthyl group, a fluorenyl group, a spiro-bifluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenalenyl group, a phenanthrenyl group, an anthracenyl group, a fluoranthenyl group, a pyrenyl group, a chrysenyl group, a naphthacenyl group, a picenyl group, a perylenyl group, a pentaphenyl group, a hexacenyl group, a pentacenyl group, a rubicenyl group, a coronenyl group, an ovalenyl group, a pyrrolyl group, a thiophenyl group, a furanyl group, a pyridinyl group, a pyrazinyl group, a pyrimidinyl group, a pyridazinyl group, a quinolinyl group, an isoquinolinyl group, a benzofuranyl group, a benzothiophenyl group, a dibenzofuranyl group, a dibenzothiophenyl group, a carbazolyl group, an indolyl group, an isoindolyl group, a benzosilolyl group, a dibenzosilolyl group, a quinolinyl group, an isoquinolinyl group, a benzimidazolyl group, an imidazopyridinyl group, —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*′(Q₃₁)(Q₃₂), and —B(Q₃₁)(Q₃₂), and Q₃₁ to Q₃₃ are each independently selected from a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, and a pyridinyl group.
 7. The organic light-emitting device of claim 1, wherein R₂₁ to R₂₇ and R₃₁ to R₃₅ are each independently selected from: hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, an imidazopyrimidine group, —Si(Q₁)(Q₂)(Q₃), —N*′(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂); and a benzene group, a pentalene group, an indene group, a naphthalene group, an azulene group, a heptalene group, an indacene group, an acenaphthalene group, a fluorene group, a spiro-bifluorene group, a spiro-benzofluorene-fluorene group, a benzofluorene group, a dibenzofluorene group, a phenalene group, a phenanthrene group, an anthracene group, a fluoranthene group, a triphenylene group, a pyrene group, a chrysene group, a naphthacene group, a picene group, a perylene group, a pentaphene group, a hexacene group, a pentacene group, a rubicene group, a coronene group, an ovalene group, a pyrrole group, a thiophene group, a furan group, a silole group, an imidazole group, a pyrazole group, a thiazole group, an isothiazole group, an oxazole group, an isoxazole group, a pyridine group, a pyrazine group, a pyrimidine group, a pyridazine group, a triazine group, a benzofuran group, a benzothiophene group, a dibenzofuran group, a dibenzothiophene group, a carbazole group, an indole group, an isoindole group, a benzosilole group, a dibenzosilole group, a quinoline group, an isoquinoline group, a benzimidazole group, an imidazopyridine group, and an imidazopyrimidine group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a C₁-C₂₀ alkyl group, a C₁-C₂₀ alkoxy group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclopentenyl group, a cyclohexenyl group, a phenyl group, a biphenyl group, and a terphenyl group, and Q₁ to Q₃ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryl group substituted with a C₁-C₆₀ alkyl group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a biphenyl group, and a terphenyl group.
 8. The organic light-emitting device of claim 1, wherein the first compound includes at least one ¹⁵N.
 9. The organic light-emitting device of claim 1, wherein the first compound includes at least one C—¹⁵N bond.
 10. The organic light-emitting device of claim 1, wherein all carbon-nitrogen single bonds in the first compound are C—¹⁵N bonds.
 11. The organic light-emitting device of claim 1, wherein the first compound is selected from Compounds 1 to 18:


12. The organic light-emitting device of claim 1, wherein at least one of the first emission layer, the second emission layer, or the third emission layer comprises a dopant and a host, and the host comprises at least one first compound.
 13. The organic light-emitting device of claim 12, wherein the host comprises at least two first compounds, at least one of the at least two first compounds is a hole transport host, and at least another one of the at least two first compounds is an electron transport host.
 14. The organic light-emitting device of claim 12, wherein the dopant does not include ¹⁵N and is different in formula structure from the first compound.
 15. The organic light-emitting device of claim 12, wherein the dopant is a fluorescent, phosphorescent, or delayed fluorescent dopant.
 16. The organic light-emitting device of claim 1, wherein at least one of the first emission layer, the second emission layer, or the third emission layer comprises a dopant and a host, and the dopant comprises at least one first compound.
 17. The organic light-emitting device of claim 16, wherein the host does not include ¹⁵N and is different in formula structure from the first compound.
 18. The organic light-emitting device of claim 1, further comprising a capping layer on the second electrode, wherein a refractive index with respect to a wavelength of about 589 nm of the capping layer is about 1.6 or more.
 19. An organic light-emitting device comprising: a first pixel electrode, a second pixel electrode, and a third pixel electrode, respectively in a first emission area, a second emission area, and a third emission area; an opposite electrode facing the first pixel electrode, the second pixel electrode, and the third pixel electrode; and an organic layer between the opposite electrode and the first pixel electrode, the second pixel electrode, and the third pixel electrode, the organic layer comprising an emission layer, wherein the emission layer comprises: a first emission layer arranged to correspond to the first emission area and to emit first-color light; a second emission layer arranged to correspond to the second emission area and to emit second-color light; and a third emission layer arranged to correspond to the third emission area and to emit third-color light, at least one of the first emission layer, the second emission layer, or the third emission layer comprises at least one first compound, and the first compound comprises at least one ¹⁵N and is represented by one of Formula 1-1, Formula 1-2, Formula 2-1 to Formula 2-3, and Formula 3:

and wherein, in Formulae 1-1, 1-2, 2-1 to 2-3, and 3, N* is ¹⁵N, and N*¹ and N*² are each independently ¹⁴N or ¹⁵N, wherein at least one of N*¹ or N*² is ¹⁵N, A₂₁ to A₂₄ and A₃₁ to A₃₃ are each independently selected from a C₃-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclic group, A₃₁ and A₃₂ are optionally linked to each other via a first linking group, X₂₁ is O, S, or N*-[(L₂₄)_(a24)-Ar₂₄], Y₂₁ and Y₂₂ are each independently a single bond, *—O—*′, *—S—*′, *—N*′(R₂₅)—*′, *—C(R₂₅)(R₂₆)—*′, *—Si(R₂₅)(R₂₆)*′, or *—C(R₂₅)═C(R₂₆)—*′, c21 and c22 are each independently an integer from 1 to 3, X₃₁ is B, P, P(═O), P(═S), Ga, As, Si(R₂₇), or Ge(R₂₇), L₁₁ to L₁₄, L₂₁ to L₂₄, and L₃₁ to L₃₅ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, L₁₅ is *—O—*′, *—S—*′, *—Se—*′, *—N*′(Ar₁₅)—*′, a substituted or unsubstituted C₃-C₆₀ carbocyclic group, or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, a11 to a14, a21 to a24, and a31 to a35 are each independently an integer from 0 to 5, a15 is an integer from 1 to 10, Ar₁₁ to Ar₁₅, Ar₂₁ to Ar₂₄, and Ar₃₁ to Ar₃₃ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, b21, b22, and b31 to b33 are each independently an integer from 0 to 10, R₂₁ to R₂₇ and R₃₁ to R₃₅ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N*(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), d21 to d24 and d31 to d33 are each independently an integer from 0 to 10, at least one substituent of the substituted C₃-C₃₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —O(Q₁₁), —S(Q₁₁), —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —P(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —O(Q₂₁), —S(Q₂₁), —Si(Q₂₁)(Q₂₂)(Q₂₃), —N*′(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —P(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and —O(Q₃₁), —S(Q₃₁), —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —P(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a C₁-C₆₀ alkyl group that is substituted with at least one selected from deuterium, —F, a cyano group, a C₁-C₆ alkyl group, a phenyl group, and a biphenyl group, and a C₆-C₆₀ aryl group that is substituted with at least one selected from deuterium, —F, a cyano group, a C₁-C₁₀ alkyl group, a phenyl group, and a biphenyl group, a nitrogen atom in the cyano group, the nitro group, the amino group, the amidino group, the hydrazine group, and the hydrazone group is ¹⁴N or ¹⁵N, N*′ is ¹⁴N or ¹⁵N, and when a heteroatom in the C₁-C₆ heterocyclic group, the C₁-C₁₀ heterocycloalkyl group, the C₁-C₁₀ heterocycloalkenyl group, the C₁-C₆₀ heteroaryl group, and the monovalent non-aromatic condensed heteropolycyclic group is each independently a nitrogen atom, the nitrogen atom is ¹⁴N or ¹⁵N, wherein * and *′ each indicate a binding site to a neighboring atom in addition to *′ in N*′.
 20. An organic light-emitting device comprising: a first electrode; a second electrode facing the first electrode; and m emission units between the first electrode and the second electrode, wherein m is an integer of 2 or more, the m emission units each comprise an organic layer including an emission layer, at least one of m emission layers included in the m emission units comprises at least one first compound, and the first compound comprises at least one ¹⁵N and is represented by one of Formula 1-1, Formula 1-2, Formula 2-1 to Formula 2-3, and Formula 3:

and wherein, in Formula 1-1, Formula 1-2, Formulae 2-1 to Formula 2-3, and Formula 3, N* is ¹⁵N, and N*¹ and N*² are each independently ¹⁴N or ¹⁵N, wherein at least one of N*¹ or N*² is ¹⁵N, A₂₁ to A₂₄ and A₃₁ to A₃₃ are each independently selected from a C₃-C₆₀ carbocyclic group and a C₁-C₆₀ heterocyclic group, A₃₁ and A₃₂ are optionally linked to each other via a first linking group, X₂₁ is O, S, or N*-[(L₂₄)_(a24)-Ar₂₄], Y₂₁ and Y₂₂ are each independently a single bond, *—O—*′, *—S—*′, *—N*′(R₂₅)—*′, *—C(R₂₅)(R₂₆)—*′, *—Si(R₂₅)(R₂₆)*′, or *—C(R₂₅)═C(R₂₆)—*′, c21 and c22 are each independently an integer from 1 to 3, X₃₁ is B, P, P(═O), P(═S), Ga, As, Si(R₂₇), or Ge(R₂₇), L₁₁ to L₁₄, L₂₁ to L₂₄, and L₃₁ to L₃₅ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, L₁₅ is *—O—*′, *—S—*′, *—Se—*′, *—N*′(Ar₁₅)*′, a substituted or unsubstituted C₃-C₆₀ carbocyclic group, or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, a11 to a14, a21 to a24, and a31 to a35 are each independently an integer from 0 to 5, a15 is an integer from 1 to 10, Ar₁₁ to Ar₁₅, Ar₂₁ to Ar₂₄, and Ar₃₁ to Ar₃₃ are each independently a substituted or unsubstituted C₃-C₆₀ carbocyclic group or a substituted or unsubstituted C₁-C₆₀ heterocyclic group, b21, b22, and b31 to b33 are each independently an integer from 0 to 10, R₂₁ to R₂₇ and R₃₁ to R₃₅ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amino group, an amidino group, a hydrazine group, a hydrazone group, a carboxylic acid group or a salt thereof, a sulfonic acid group or a salt thereof, a phosphoric acid group or a salt thereof, a substituted or unsubstituted C₁-C₆₀ alkyl group, a substituted or unsubstituted C₂-C₆₀ alkenyl group, a substituted or unsubstituted C₂-C₆₀ alkynyl group, a substituted or unsubstituted C₁-C₆₀ alkoxy group, a substituted or unsubstituted C₃-C₁₀ cycloalkyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkyl group, a substituted or unsubstituted C₃-C₁₀ cycloalkenyl group, a substituted or unsubstituted C₁-C₁₀ heterocycloalkenyl group, a substituted or unsubstituted C₆-C₆₀ aryl group, a substituted or unsubstituted C₆-C₆₀ aryloxy group, a substituted or unsubstituted C₆-C₆₀ arylthio group, a substituted or unsubstituted C₁-C₆₀ heteroaryl group, a substituted or unsubstituted monovalent non-aromatic condensed polycyclic group, a substituted or unsubstituted monovalent non-aromatic condensed heteropolycyclic group, —Si(Q₁)(Q₂)(Q₃), —N*(Q₁)(Q₂), —B(Q₁)(Q₂), —S(═O)₂(Q₁), and —P(═O)(Q₁)(Q₂), d21 to d24 and d31 to d33 are each independently an integer from 0 to 10, at least one substituent of the substituted C₃-C₃₀ carbocyclic group, the substituted C₁-C₆₀ heterocyclic group, the substituted C₁-C₆ alkyl group, the substituted C₂-C₆₀ alkenyl group, the substituted C₂-C₆₀ alkynyl group, the substituted C₁-C₆ alkoxy group, the substituted C₃-C₁₀ cycloalkyl group, the substituted C₁-C₁₀ heterocycloalkyl group, the substituted C₃-C₁₀ cycloalkenyl group, the substituted C₁-C₁₀ heterocycloalkenyl group, the substituted C₆-C₆₀ aryl group, the substituted C₆-C₆₀ aryloxy group, the substituted C₆-C₆₀ arylthio group, the substituted C₁-C₆₀ heteroaryl group, the substituted monovalent non-aromatic condensed polycyclic group, and the substituted monovalent non-aromatic condensed heteropolycyclic group is selected from: deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group; a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, and a C₁-C₆₀ alkoxy group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —O(Q₁₁), —S(Q₁₁), —Si(Q₁₁)(Q₁₂)(Q₁₃), —N(Q₁₁)(Q₁₂), —B(Q₁₁)(Q₁₂), —P(Q₁₁)(Q₁₂), —C(═O)(Q₁₁), —S(═O)₂(Q₁₁), and —P(═O)(Q₁₁)(Q₁₂); a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group; a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, and a monovalent non-aromatic condensed heteropolycyclic group, each substituted with at least one selected from deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, —O(Q₂₁), —S(Q₂₁), —Si(Q₂₁)(Q₂₂)(Q₂₃), —N*′(Q₂₁)(Q₂₂), —B(Q₂₁)(Q₂₂), —P(Q₂₁)(Q₂₂), —C(═O)(Q₂₁), —S(═O)₂(Q₂₁), and —P(═O)(Q₂₁)(Q₂₂); and —O(Q₃₁), —S(Q₃₁), —Si(Q₃₁)(Q₃₂)(Q₃₃), —N*(Q₃₁)(Q₃₂), —B(Q₃₁)(Q₃₂), —P(Q₃₁)(Q₃₂), —C(═O)(Q₃₁), —S(═O)₂(Q₃₁), and —P(═O)(Q₃₁)(Q₃₂), Q₁ to Q₃, Q₁₁ to Q₁₃, Q₂₁ to Q₂₃, and Q₃₁ to Q₃₃ are each independently selected from hydrogen, deuterium, —F, —Cl, —Br, —I, a hydroxyl group, a cyano group, a nitro group, an amidino group, a hydrazine group, a hydrazone group, a C₁-C₆₀ alkyl group, a C₂-C₆₀ alkenyl group, a C₂-C₆₀ alkynyl group, a C₁-C₆₀ alkoxy group, a C₃-C₁₀ cycloalkyl group, a C₁-C₁₀ heterocycloalkyl group, a C₃-C₁₀ cycloalkenyl group, a C₁-C₁₀ heterocycloalkenyl group, a C₆-C₆₀ aryl group, a C₆-C₆₀ aryloxy group, a C₆-C₆₀ arylthio group, a C₁-C₆₀ heteroaryl group, a monovalent non-aromatic condensed polycyclic group, a monovalent non-aromatic condensed heteropolycyclic group, a C₁-C₆₀ alkyl group that is substituted with at least one selected from deuterium, —F, a cyano group, a C₁-C₆ alkyl group, a phenyl group, and a biphenyl group, and a C₆-C₆₀ aryl group that is substituted with at least one selected from deuterium, —F, a cyano group, a C₁-C₁₀ alkyl group, a phenyl group, and a biphenyl group, a nitrogen atom in the cyano group, the nitro group, the amino group, the amidino group, the hydrazine group, and the hydrazone group is ¹⁴N or ¹⁵N, N*′ is ¹⁴N or ¹⁵N, and when a heteroatom in the C₁-C₆ heterocyclic group, the C₁-C₁₀ heterocycloalkyl group, the C₁-C₁₀ heterocycloalkenyl group, the C₁-C₆₀ heteroaryl group, and the monovalent non-aromatic condensed heteropolycyclic group is each independently a nitrogen atom, the nitrogen atom is ¹⁴N or ¹⁵N, wherein * and *′ each indicate a binding site to a neighboring atom in addition to *′ in N*′. 